PIK3CA and central nervous system cancer: In this study, differentially expressed novel_circ_000481 host gene PIK3CA (encoding p110) and novel_circ_013299 host gene PIK3R1 (encoding p85α) were significantly enriched in the B-cell receptor signaling pathway, glioma, the FoxO signaling pathway, prostate cancer, and other pathways, which were up-regulated in adolescent goats.