ATX, which is encoded by the ENPP2 gene, is responsible for the generation of LPA from LPC and has been shown to be overexpressed in a number of tumour types, such as melanoma (Sun et al., 2016) and cancers of the thyroid (Benesch et al., 2015), breast (Yang et al., 2002), pancreas (Nakai et al., 2011) and stomach (Zeng et al., 2017), leading to increased levels of LPA in tumours (Nakai et al., 2011; Zeng et al., 2017). This evidence concerns the gene ENPP2 and melanoma.