The reduction of RP-S6 phosphorylation by each of the gero-suppressive drugs was presently observed in all types of the cells, including tumor TK6 (Fig. 1-3,7) and A549 (Fig. 4) cell lines as well as in normal WI-38 (Fig. 5) and mitogenically stimulated human lymphocytes (Fig. 6). Here, RPS6 is linked to neoplasm.