RB1 and cancer: This segment contained additional candidate genes (Figure 3A) that may contribute to cancer progression; Interesting targets include two neighbor genes flanking RB1, namely ITM2B and RCBTB2, as well as P2RY5, which is located inside RB1. Indeed, Lee et al. (2007) reported that ITM2B and P2RY5 modulated cell survival and were silenced by methylation or point mutations, respectively.