APC and colorectal carcinoma: APC mutations are prevalent in CIN-CRC [3], but the Wnt pathway gene mutation spectrum in MSI-CRC is less well characterized, with mutations in the Axin homolog AXIN2 and the TCF-family transcription factor TCF7L2 identified in ∼25% and ∼35% of MSI-CRC, respectively [8], [9].