Also were found in this cluster: E2F5, a member of the E2F transcriptional factors family, which plays a role as repressor during G1 phase [27], the retinoblastoma protein (RB1), a main tumor suppressor which inhibits cell cycle progression during this phase by inactivating E2F1 [28] and CDC73, another tumor suppressor which has been reported to interact with cyclin D1 [29]. The gene discussed is RB1; the disease is neoplasm.