First, as is shown in the heatmap (Fig. S4a), ACE2 was positively and significantly associated with the infiltration of at least two types of immune cells in BLCA, breast invasive carcinoma (BRCA), KIRC, OV, PAAD, PRAD, READ, primary skin cutaneous melanoma (SKCM), thyroid carcinoma (THCA) and uterine corpus endometrial carcinoma (UCEC). The gene discussed is ACE2; the disease is bladder transitional cell carcinoma.