RB1 and hepatocellular carcinoma: Another study reported that let-7C affected cell cycle and growth of hepatocellular carcinoma cells via interference with the differential expression of several cell cycle proteins including M-phase inducer phosphatase 1 (CDC25A), cyclin D1, cyclin dependent kinase (CDK) 6, retinoblastoma (pRb) and E2F transcription factor 2 (E2F2) [83].