The downstream interaction of HNF1B is currently poorly understood, but based on the animal model it has been suggested that the downregulation of HNF1B during tumor progression is associated with the upregulation of enoyl-CoA-(Δ) isomerase 2 (ECI2) protein levels, which is one of the possible downstream targets of HNF1B31. The gene discussed is HNF1B; the disease is neoplasm.