The Spearman correlation analysis using the TISIDB database revealed a significant positive correlation between CD318 and the abundance of Treg cells in the tumor microenvironment of LUAD and CESC (p = 9.39 × 10−10 and p = 0.00135, respectively) vs. a non-significant correlation in COAD, as expected (Figure 4D(i–iv)). The gene discussed is CDCP1; the disease is neoplasm.