CDK4 and lung cancer: For instance, miR‐503‐5p represses the cell viability of lung cancer cells and induces apoptosis via modulating the p21 and CDK4 expression (Sun, Li, et al., 2017); miR‐503‐5p restrains CD97‐Mediated JAK2/STAT3 signaling pathway and impedes metastasis of ovarian cancer (Sun, Li, et al., 2017).