CDK4 and neoplasm: One tumour had a large (>130 kb) deletion on chromosome 9p21 affecting several genes including tumour suppressor CDKN2A, which encodes both the CDK4/6 interacting p16-IN4A protein, but also the p14-ARF protein that has a function in the MDM2-TP53 pathway, thus it is relevant in ovarian tumours.