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UNITED STATES
SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

FORM 6-K
 
Report of Foreign Private Issuer
Pursuant to Rule 13a-16 or 15d-16 of
the Securities Exchange Act of 1934

Date of Report: March 29, 2017
Commission File Number: 001-36891

Indicate by check mark whether the registrant files or will file annual reports under cover of Form 20-F or Form 40-F:
Form 20-F ☑ Form 40-F ⃞

Indicate by check mark if the registrant is submitting the Form 6-K in paper as permitted by Regulation S-T Rule 101(b)(1): ⃞

Indicate by check mark if the registrant is submitting the Form 6-K in paper as permitted by Regulation S-T Rule 101(b)(7): ⃞

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EXHIBIT INDEX

SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned, thereunto duly authorized.

3

Exhibit 99.1

Cellectis to Present at the 2017 Annual Conference of the American Association for Cancer Research

NEW YORK--(BUSINESS WIRE)--March 29, 2017--Regulatory News:

Cellectis (Paris:ALCLS) (NASDAQ:CLLS) (Alternext: ALCLS; Nasdaq: CLLS), a biopharmaceutical company focused on developing immunotherapies based on gene edited CAR T-cells (UCART), today announced that data on its gene-edited allogeneic CAR T-cells will be presented at the American Association for Cancer Research (AACR) Annual Meeting. This includes both wholly-controlled Cellectis programs and Pfizer/Cellectis collaboration programs. The meeting will be held from April 1st to April 5th, 2017 in Washington, D.C., USA.

Cellectis presentation:

• UCART22: An Allogeneic Adoptive Immunotherapy for Leukemia Targeting CD22 with CAR T-cells

Agnès Gouble¹, Cécile Schiffer-Mannioui¹, Séverine Thomas¹, Anne-Sophie Gautron¹, Laurent Poirot¹, Julianne Smith².
¹Cellectis, Paris, France; ²Cellectis, New York, NY

Innate Effectors in Immunity to Cancer session – section 30
April 4, 2017, 8:00 AM - 12:00 PM Eastern Time

Pfizer/Cellectis presentations:

• Allogeneic EGFRvIII Chimeric Antigen Receptor T Cells for Treatment of Glioblastoma

Oi Kwan Wong¹, Mathilde Dusseaux², Jing-Tyan Ma¹, Melinda Au¹, Sophie Leduc², Joyce Chou¹, Jessica M. Yu¹, Marjorie Bateman¹, Thomas Pertel¹, Kevin C. Lindquist¹, Julianne Smith³, Barbra Sasu¹, Shu-Hui Liu¹.
¹Pfizer Inc., South San Francisco, CA; ²Cellectis, Paris, France; ³Cellectis, New York, USA

Innate Effectors in Immunity to Cancer session – section 30
April 4, 2017, 8:00 AM - 12:00 PM Eastern Time

• Differential modulation of the PD-1 pathway impacts the anti-tumor activity of CAR T cells

Regina J. Lin¹, Anne-Sophie Gautron², Laurent Poirot², Oi Kwan Wong¹, Barbra Sasu¹, Bijan Boldajipour¹.
¹Pfizer, South San Francisco, CA; ²Cellectis, Paris, France; ³Cellectis, New York, USA

Late-Breaking Research: Immunology session – section 35
April 4, 2017, 8:00 AM - 12:00 PM Eastern Time

Collaboration with Pfizer

In June 2014, Cellectis and Pfizer began collaborating on a joint clinical development program for UCAR-T therapies, in the field of oncology, directed at numerous targets selected by Pfizer and several targets selected by Cellectis.

About Cellectis

Cellectis is a biopharmaceutical company focused on developing immunotherapies based on gene-edited CAR T-cells (UCART). The company’s mission is to develop a new generation of cancer therapies based on engineered T-cells. Cellectis capitalizes on its 17 years of expertise in genome engineering - based on its flagship TALEN® products and meganucleases as well as its pioneering electroporation PulseAgile technology - to create a new generation of immunotherapies. CAR technologies are designed to target surface antigens expressed on cells. Using its life-science-focused, pioneering genome-engineering technologies, Cellectis’ goal is to create innovative products in multiple fields and with various target markets.

Cellectis is listed on the Nasdaq market (ticker: CLLS) and on the NYSE Alternext market (ticker: ALCLS). To find out more about us, visit our website: www.cellectis.com

Talking about gene editing? We do it. TALEN® is a registered trademark owned by the Cellectis Group

Disclaimer

This press release and the information contained herein do not constitute an offer to sell or subscribe, or a solicitation of an offer to buy or subscribe, for shares in Cellectis in any country. This press release contains forward-looking statements that relate to the Company’s objectives based on the current expectations and assumptions of the Company’s management only and involve risk and uncertainties that could cause the Company to fail to achieve the objectives expressed by the forward-looking statements above.

CONTACT:
Media:
Cellectis
Jennifer Moore, 917-580-1088
VP of Communications
media@cellectis.com
or
KCSA Strategic Communications
Caitlin Kasunich, 212-896-1241
ckasunich@kcsa.com
or
IR:
Cellectis
Simon Harnest, 646-385-9008
VP of Corporate Strategy and Finance
simon.harnest@cellectis.com