BIRC5 and colorectal cancer: As shown in Fig. 1c, we performed co-immunoprecipitation of survivin and XIAP in colorectal cancer cells HCT116 and RKO, and found that survivin-immunocomplexes contained XIAP, and XIAP-immunocomplexes also contained survivin, demonstrating that these two proteins can form survivin-XIAP complex in colorectal cancer cells.