ADH4 and melanoma: The remaining two SNPs were located in the alcohol dehydrogenase 4/5 genes (ADH4/5) and in the ATP-binding cassette sub-family B member 5 gene (ABCB5), respectively; the former are genes responsible for the metabolism of alcohol substrates, while the latter gene is involved in the development of drug (doxorubicin) resistance to melanoma treatment.