As a result, we detected a positive relation between the KDM6B expression and the immune infiltration level of Treg in COAD and LUSC; endothelial cell and COAD, KIRC, PAAD (pancreatic adenocarcinoma), SKCM (skin cutaneous melanoma)-metastasis, and STAD (stomach adenocarcinoma); neutrophil and PCGC (pheochromocytoma and paraganglioma), PRAD, and THCA; and follicular helper T cells and GBM (glioblastoma multiforme) and UCEC (uterine corpus endometrial carcinoma). This evidence concerns the gene KDM6B and pheochromocytoma.