RB1 and cancer: In this early stage of the tumor progression, cancer cells show an increase in the frequency of additional genetic abnormalities such as number of chromosomes, single point mutations, translocations, deletions, and amplifications of genes namely TP53, RB1, EGFR, and KRAS, among others (7), which are responsible for promoting metabolic and morphological changes that sustain the proliferation of cancer cells (2, 4, 5, 8) (Figure 1B).