SERPINA1 expression was confirmed to be associated with immune subtypes in ACC, BLCA, BRCA, KICH, KIRC, LGG, LUAD, LUSC, OV (ovarian serous cystadenocarcinoma), PCPG (pheochromocytoma and paraganglioma), PRAD (prostate adenocarcinoma), SARC, SKCM, THCA, UCEC, and UVM (uveal melanoma) (Figure 4). Here, SERPINA1 is linked to pheochromocytoma.