RB1 and neoplasm: Characterisation of senescent cells can be performed by assessing multiple markers such as an enlarged morphology, activation of p53-p21 and/or p16-Rb tumour suppressor pathways, induction of p16INK4a, the presence of persistent DNA damage response, an increase in β-galactosidae (β-gal+) expression, and the appearance of senescent-associated distension of satellites and telomere-associated DNA damage foci [32,33].