RPS6KB1 and cancer: We note that the RxRxxS/T motif can also be phosphorylated by RSK and S6K, which promote cell proliferation and growth.43 In certain cancer cells, the designed peptide is likely to be phosphorylated by all of the three kinases, which trigger the core Akt-RSK-S6K signaling pathways that are activated at the downstream of protooncogenic receptor protein kinases.43