ACAP2 and cancer: For examples, circRNA_102171 boosts papillary thyroid cancer progression via modulation of CTNNBIP1‐dependent activated β‐catenin pathway,24 the circRNA‐ACAP2‐miR‐21‐5p‐Tiam1 feedback loop impacts the proliferation, migration and invasion capacities of SW480 cells,25 and circRNA ZNF609 serves as a competitive endogenous RNA of FOXP4 by absorbing miR‐138‐5p in renal carcinoma.26 However, the investigation of circRNAs in cancers was still inadequate.