Regarding CCND2 mRNA expression, 91.8% (45/49) of lung adenocarcinoma patients, 84.9% (62/73) of breast cancer patients, and 100% (7/7) of TNBC patients showed CCND2 mRNA downregulation in tumors when compared with that in adjacent normal tissues (Table 1, Figure 3A, all p < 0.001), but the difference was not significant in esophageal, gastric, liver, and colon cancers (Table 1 and Figure 3A). Here, CCND2 is linked to breast carcinoma.