PDCD4 and hepatocellular carcinoma: miR-21 was also detected to overexpress in SP cells of HCC and increase the ability of migration and invasion via degradation of tumour suppressors phosphatase and tensin homolog (PTEN), reversion-inducing-cysteine-rich protein with kazal motifs (RECK) and programmed cell death 4 (PDCD4) [8].