CDKN1B and gastric cancer: These models are particularly relevant as tumor suppressor gene inactivation is a hallmark of human gastric cancer, with frequent alterations in genes such as TP53, RUNX3, APC, and CDKN1B/p27 depending on the tumor subtype (Choi et al., 2018; Tsang et al., 2011; Tsang et al., 2010; Chen et al., 2010; Bencivenga et al., 2021).