RBP1 and renal agenesis: Dual immunofluorescence showed co-expression of cRBP-1 and αSMA in scattered cells, which are presumably in various stages of transition between stellate cells and mesenchymal cells based on morphological and immunophenotypic features, in bilateral renal agenesis (Fig.3), whereas co-expression of these antigens was present in fewer hepatic stellate cells in control fetuses.