LDB1 and carcinoma: These differential roles of LDB1 according to tumor location may be explained by the varying levels of Wnt activity on proximal and distal CRC: Proximal carcinomas upregulate the Wnt pathway to a lesser extent than distal tumors; therefore, LDB1 may upregulate Wnt in proximal tumors more easily than in distal tumors, which already exhibit high Wnt signaling activity.