These studies show that STAT5 is essential for AKT–p70 S6K activity during lymphocyte proliferation in patients with leukemias and lymphomas (Lockyer et al., 2007), and that AKT–mTOR–p70 S6K, ERK, and NF-κB were involved together in proliferation of osteosarcoma cells (Miwa et al., 2012). This evidence concerns the gene RPS6KB1 and osteosarcoma.