PAT1 and PAT4 modulate the activity of the mTORC1 signalling cascade in MCF-7 breast cancer cells. Lysates from MCF-7 cells grown in medium containing 10% serum treated for 120 h with siRNA against PAT1 (si158, si159 and si160), PAT4 (si435, si436 and si437) and mTOR (si825) were compared to control lysates from cells treated with a scrambled siRNA (sc) or lipofectamine™ only (lp) by probing with anti-Phospho-T389-p70 S6K1 (P-T389-S6K1) and anti-Phospho-T24-FoxO1/T32-FoxO3a (P-FoxO1/3a; A), anti-Phospho-S240/244-S6 (P-S240/244-S6) and anti-Phospho-S65-4E-BP1 (P-S65-4E-BP1; B), as well as non-Phospho-specific antisera against S6K1 and 4E-BP1, and an anti-α-tubulin antibody to confirm equal loading. All experiments were repeated at least three times with similar results.