To analyze whether XPO5 knockdown suppresses colorectal cancer (CRC) tumorigenicity, SW480 cells transfected with either XPO5 siRNA (siXPO5) or control siRNA (siControl) were injected subcutaneously in nude mice (106 cells per mouse) to generate a xenograft model. (A) At 12 days post-injection, tumor volume and weight in recipients of siXPO5-transfected cells were significantly decreased relative to those in recipients of siControl-transfected cells (P=0.0002 volume; P=0.0004 weight). (B) XPO5, miR-21, and miR-182 expression levels were significantly lower in siXPO5 tumors than in scramble-control transfected tumors at the end of the experiment (P<0.05). *P<0.05, **P<0.01, ***P<0.001