GUCY2C and colorectal carcinoma: To further categorize these biomarkers based on their functional mechanisms, mRNA biomarkers such as SOX9, GSK3A, GUCY2C, B2M, TIM-1, and CLU are involved in various pathways that regulate the development and progression of CRC, including the Wnt/β-catenin pathway [84,97], PI3K/AKT/mTOR pathway [84], cyclic guanosine monophosphate (cGMP) signaling pathway [86], major histocompatibility complex (MHC) class I pathway [87], immune response regulation, and apoptotic pathway [87].