For example, exosomal cholangiocarcinoma (CCA)-associated circular RNA 1 (circ-CCAC1) derived from ERBB2 gene was discovered to sponge miR-514a-5p to upregulate Yin Yang 1 (YY1), inducing CCA angiogenesis, and regulate CCA tumorigenesis and metastasis [245]. Here, YY1 is linked to cholangiocarcinoma.