KRAS and colorectal carcinoma: Ectopic expression of let-7c in highly metastatic Lovo CRC cells significantly suppressed cell migration and invasion in vitro through the downregulation of KRAS, MMP11 and PBX3. In contrast, the inhibition of let-7c in poorly metastatic HT29 cells increased cell motility and invasion through increased gene expression of its targets KRAS, MMP11 and PBX3 [376].