The marginal eQTL signal also coincided with a highly significant tsQTL, indicative of two independent genetic mechanisms (microenvironment and tumor) operating through ERAP2. Interestingly, a previous study found that ERAP2 expression was limited to epithelial cells in normal tissue, and loss of this enzyme was found in 86% of tumors [63]. This evidence concerns the gene ERAP2 and neoplasm.