SMAD4 and cervical squamous cell carcinoma: Commonly mutated genes in the TGFβ pathway include TGFBR2 (a receptor), CREB binding protein (CREBBP) and E1A binding protein p300 (EP300) (activators), and SMAD4 (a transcription factor and tumor suppressor), and mutations in at least one of these genes have been reported in 30% of cervical squamous cell carcinomas [18].