CCND1 and prostate cancer: MiR-19a has been found to promote cell proliferation in various types of cancers such as bladder cancer, gastric cancer, prostate cancer via targeting different transcriptional factors [16, 42, 43]; and in HCC patients, miR-19a was found to be up-regulated in the blood serum, and played inhibitory roles in HCC via regulating cyclin D1 expression [28], Melegari et al., further demonstrated miR-19a was up-regulated in HBV-positive HCC and this up-regulation is attributed to HBx [44].