MAPK1 and intrahepatic cholangiocarcinoma: MAPK1 plays a critical role in intrahepatic cholangiocarcinoma (ICC) by being recruited by osteopontin (OPN) to phosphorylate β-Catenin at SER675, thereby enhancing nuclear accumulation and activating the Wnt/β-Catenin pathway, key drivers of tumor growth and metastasis [70].