Based on our analysis, we found that CCND1/CDK4/PLK1/CD44 signatures were linked with shorter survival percentages in a group of multiple cancer types, including bladder carcinoma, breast cancer, colon adenocarcinoma, glioblastoma multiforme, head and neck cancers, leukemia, NSCLC, and ovarian cancer (Figure 3). This evidence concerns the gene CDK4 and breast cancer.