ID2 and Familial prostate cancer: Other studies have also reported that ID2 is upregulated in brain cancer, colon cancer, pancreatic cancer, and prostate cancer, in which it promotes tumor progression, making it an unfavorable prognostic factor (Niola et al., 2013; Wilson et al., 2001; Maruyama et al., 1999; Coppe et al., 2004).