PIK3CG and cancer: Furthermore, evidence has showed that circRNAs could regulate most critical signaling pathways in cancer including Wnt [7], PIK3/AKT [8], and MAPK/ERK [9] pathways and deregulated expression of circRNAs in many types of cancers, including GC [10], bladder cancer [11], breast cancer [12], colorectal cancer [13], lung cancer [14], and so on.