In order to test the working hypotheses that Trx-dependent metabolism also represented a significant determinant of melanoma sensitivity to TPP, clonogenic assays were performed using A375 treated with TPP derivatives (0.5 μM) with chain lengths of 10–16 carbons alone or in combination with 1.0 μM AUR, a known inhibitor of TrxR (Fig 5C). This evidence concerns the gene TXN and melanoma.