MKI67 and neoplasm: In p53-mutated tumors, CDK6 expression was significantly associated with tumor size (p = 0.047), tumor grade (p = 0.008), histologic subtype (p < 0.001), molecular subtype (p = 0.017), NPI (p = 0.039), and Ki67 proliferative index (p = 0.03) (Supplementary Table 6).