N6-Isopentenyladenosine (Riboprine), an RNA modification found in cytokinins, which regulate plant growth/differentiation, and a subset of tRNAs, where it improves the efficiency and accuracy of translation. N6-Isopentenyladenosine, an end product of the mevalonate pathway, is an autophagy inhibitor with an interesting anti-melanoma activity[1][2][3].