Since EZH2 was overexpressed in IBC cells and EZH2 expression positively correlates with tumor spheroid growth and tumorigenicity in FC-IBC-02 cells, we sought to determine the effects of EZH2 knockdown on tumor spheroid formation of IBC cells in vitro and the tumorigenicity of IBC in vivo in an orthotopic xenograft model in immunodeficient mice. Here, EZH2 is linked to inflammatory breast carcinoma.