CCND1 and cancer: In NSCLC, circRNA ITCH is reported markedly decreased in cancer tissues with negative regulation on the proliferation of cancer cells by down-regulating oncogenic miR-7 and miR-214 as well as up-regulating T-cell factor, β-catenin, c-Myc, and cyclin D1, thereby enhancing the activation of the Wnt/β-catenin signaling pathway (Wan et al., 2016).