Based on the results of the metabolomic analysis, we used a secondary validation assay to monitor changes in pipecolic acid after knocking down ASAH1. In complete agreement with the results of the metabolomic analysis, knockdown of ASAH1 in melanoma cell lines (A375, M14, MeWo, and YUGASP) resulted in reduced pipecolic acid levels (Figure 5B). Here, ASAH1 is linked to melanoma.