TOP1 and colorectal carcinoma: The second gene that was related to CRC identified in this study was phospholipase C gamma 1 (PLCG1), which is a signaling molecule and is a neighboring gene of TOP1. PLCG1 is activated in response to growth factor stimulation and is involved in the regulation of a variety of cellular functions such as cell migration, invasion and metastasis [29], [30], [31].