RBL1 and breast cancer: Interestingly, RBL2 CNAs are most frequent in luminal breast cancers (PAM50 gene-centric frequencies of somatic aberrations via gene loss for LumA = 0.592275 and LumB=0.492537) but are also found in the basal subgroup (Basal = 0.262712; Supplementary Fig. 9g), while RBL2 CNAs are frequent in breast cancer subgroups with a poor disease prognosis such as Cluster 2 (gene-centric frequencies of somatic aberrations via gene loss for RBL2 = 0.533333 vs pRb = 0.4 vs RBL1 = 0.022222; Supplementary Fig. 9g, h).