Thus important in this context, Li et al. (2017a) demonstrated that in p53-mutant MDA-MB-231 but not normal breast cells, low doses of 50–200 mGy X-rays at 12.5 kV accelerated cell growth, induced an accumulation of mutant p53 and upregulated the expression of cyclin-dependent kinases CDK4, CDK6 and cyclin D1, which are involved in the development and survival of numerous cancer types (Goel et al. 2022). Here, CDK4 is linked to cancer.