ACAP2 and melanoma: CircRNAs have been reported to sponge miRNA and regulate gene expression.12 In malignant melanoma, hsa_circ_0025039 promotes cell growth, invasion and glucose metabolism via sponging miR‐198.13 In colon cancer, circRNA‐ACAP2 sponges miR‐21‐5p to regulate cell proliferation, migration and invasion.14 In ovarian cancer, hsa_circ_0061140 affects cell growth and metastasis through sponging miR‐370.15 Here, we found that circEPSTI1 could bind to miR‐942 and acted as a miRNA sponge.