PFKFB3 and pheochromocytoma-paraganglioma: Intriguingly, our results show that PFKFB3 expression was remarkably significantly correlated with the expression of almost all these immune checkpoint markers in 17 types of tumors, including BLCA, LAML, PAAD, LUAD, OV, MESO, LIHC, LGG, STAD, READ, COAD, UVM, KICH, pheochromocytoma and paraganglioma (PCPG), KIRP, PRAD, and THCA (Figure 4B).