While the ongoing clinical trials will determine whether these mTOR kinase inhibitors are effective in clinical treatment of colorectal carcinomas, preclinical study of the carcinoma cell lines reveals the resistance of many of the cell lines to the treatment of the mTOR kinase inhibitor PP242 in part due to mTOR-independent 4E-BP1 phosphorylation [48]. This evidence concerns the gene EIF4EBP1 and colorectal carcinoma.