MTOR and colorectal cancer: Let-7e, in fact, belongs to the let-7 family of oncosuppressive miRNAs acting on key oncogenes, such as Ras, MYC and CDK658 whereas miR-99b targets IGF-1R in human keratinocytes, mTOR in colorectal cancer cells, and FGFR3 in non-small lung cancer59, 60.