The remarkable clinical benefits of CDKi, along with other matched therapies and its relevance, have sparked interest beyond the realm of BC, including in the non-small cell lung, colorectal or pancreatic cancers (KRAS-mutant) [98,115,116], pediatric cancers [117], ovarian [118]/endometrial cancers [119], and other solid tumors that exhibit loss of cell cycle regulation due to downregulated/mutated tumor suppressor genes (CDKN2A, CDKN2B) and overexpression of many of the cell-cycle-associated oncoproteins such as Cyclin D, as well as cyclin-dependent kinases [120,121]. The gene discussed is KRAS; the disease is breast cancer.