Melanoma-derived PAEP significantly inhibited the secretion of both IL-2 (113.8 ± 8.6 pg/ml, 624.38-Mel shControl group vs. 219.2 ± 6.3 pg/ml, 624.38-Mel shPAEP group, decreased by 48.1%, p<0.05) and IFN-γ (79.2 ± 1.3 pg/ml, 624.38-Mel shControl group vs. 137.2 ± 3.8 pg/ml, 624.38-Mel shPAEP group, decreased by 42.3%, p<0.05) but did not affect the PHA-stimulated secretion of IL-4 and IL-5 (Fig. 2E). Here, IL2 is linked to melanoma.