Because it was reported that N-glycolylneuraminic acid synthesis could not occur in human cells due to a 92 bp sequence deletion in the CMAH gene that blocks the synthesis of a functional form of CMP-NeuAc hydroxylase (CMAH), the enzyme responsible for the conversion of CMP-N-acetylneuraminic acid into CMP-N-glycolylneuraminic acid [38, 39], firstly we explored if this genetic alteration was reverted in melanoma cells. Here, CMAHP is linked to melanoma.