Additionally, a germline deletion of the CDKN1B gene in mice was utilized to validate a mouse model of colorectal cancer resulting from TGF-β-dependent T-cell-specific loss of Smad4 (Smad4TKO), which indicated that the loss of CDKN1B was related to aggressive tumor behavior and a poor clinical outcome in cancers [15]. The gene discussed is CDKN1B; the disease is colorectal cancer.