RPS6KB1 and renal cell carcinoma associated with Xp11.2 translocations/TFE3 gene fusions: Phosphorylation of canonical (p70 S6K) and non-canonical (TFEB) mTORC1 substrates and downstream signaling intermediates (S6) was generally elevated in the tRCC cell lines with SFPQ-TFE3 (UOK145), PRCC-TFE3 (UOK120, UOK124, UOK146) and NONO-TFE3 (UOK109) fusion expression, compared to ccRCC controls (UOK111, UOK140 and UOK150) (Fig. 3F).