RPS6KB1 and neoplasm: Moreover, metformin has been shown to inhibit the activation of the p70S6K pathway independently of AMPK (Vazquez-Martin et al., 2009) in tumour cells and p70S6K has been shown to be required for the growth hormone-dependent adipose conversion of 3T3-F442A preadipocytes (Yarwood et al., 1999).