TGFB1 and carcinoma: Using a conditional TGF-β RII knock-out mice model, Guasch et al. found that highly proliferative epithelia (such as rectal and genital) developed spontaneous squamous cell carcinomas and furthermore showed accelerated carcinoma progression, Ras mutations, and apoptosis reduction [86], suggesting that a deficient TGF-β pathway contributes to tumorigenesis.