Human scrambled shRNA, FIP200 shRNA, and Tsc1 shRNA encoded in pGIPZ lentiviral vector were purchased from Open Biosystems (Lafayette, CO). Mouse scrambled shRNA, LAL shRNA #1 and #2 were purchased from Sigma. Package vectors of pSPAX2 and pMD2.G were mixed with shRNA vectors and transfected in HK293 cells for virus production essentially as described before37 (link).