Additionally, the CD44 expression in diverse cancer pathological stages was analyzed based on GEPIA database, as a result, CD44 expression related to the clinical pathological stages of breast invasive carcinoma (BRCA), pancreatic adenocarcinoma (PAAD), skin cutaneous melanoma (SKCM), and STAD (Figure 1D). The gene discussed is CD44; the disease is invasive breast carcinoma.