SMAD5 and cancer: In addition, we compared SMAD5 expression between 347 cancer and 50 adjacent normal tissues, and found significantly greater expression in CRC samples (P = 6.56 × 10−7, CRC tissue: 1323 ± 423 RPKM (reads per kilobases per million reads), peritumor tissue: 1020 ± 294 RPKM).