PDCD4 and nasopharyngeal carcinoma: Consistent with this observation, miR21 is an oncogenic miRNA that targets pro-apoptotic PTEN (phosphatase and tensin homolog) and PDCD4 (programmed cell death 4 gene) expression (Iliopoulos et al. 2010) and increases the migratory potential of a human keratinocyte cell line (Lu et al. 2015), nasopharyngeal carcinoma (Qiu et al. 2015), and colorectal cancer (Ferraro et al. 2014).