ENPP2 and melanoma: Although ATX inhibition contributes greatly to therapeutic efficacy against melanoma [24], the effect of thio-ccPA 18:1 on viability is not only related ATX inhibition since neither LPA nor a stabilized LPA analog, R-OMPT [28] that would bypass the inhibition of ATX, were able to override the inhibitory effects of thio-ccPA 18:1.