Among the nine immune checkpoint related genes, excluding cancer types that did not have statistical significance (p > 0.05), the expression of CD276, HMGB1, and BTN3A1 in tumors was positively correlated with FOXK2 expression (Figure S6c,d,h); VTCN1, IL2RA, ICOSLG, ICAM1, BTN3A1, CD27, and FOXK2 expressions were positively correlated in some cancer types and negatively correlated in others (Figure S6a,b,e–g,i). The gene discussed is FOXK2; the disease is cancer.