Furthermore, CDK6 was negatively correlated with tumor purity in BRCA (r = −0.31833, p = 7.21 × 10−25), head and neck squamous cell carcinomas (HNSCs) (r = −0.06379, p = 0.157308), LIHC (r = −0.11342, p = 0.034946), and LUADs (r = −0.16182, p = 0.000304). Here, CDK6 is linked to head and neck squamous cell carcinoma.