ERAP1 and neoplasm: In some cases, ERAPs’ activity has been shown to enhance the immune system’s ability to recognize and eliminate cancer cells, as seen in thyroid (Compagnone et al., 2019) and colon cancers (Fruci et al., 2008); conversely, in other disease contexts, such as for melanoma and renal cell carcinoma, the rs30187 and rs27044 ERAP1 variants seem to be responsible for immune evasion, altering peptide trimming in ways that may reduce tumor cell visibility to CD8+ T cells, thus promoting progression and metastasis formation (Cifaldi et al., 2012; Stratikos, 2014).