RPS6KA1 and melanoma: It has previously been reported that phosphorylation of EPHA2 on S897 can be mediated by AKT and RSK.22, 23 Recently, it has also been shown that the specific AKT1 promotes melanoma metastasis and also mediates EPHA2 S897 phosphorylation.24, 25 We therefore investigated if the CD13 blocking antibody had an effect on AKT1 and RSK phosphorylation.