RBP4 and neoplasm: We also assessed the effect of RBP4 overexpression on STAT3 phosphorylation in 67NR/RBP4 cells in vitro (as well as in 67NR/RBP4 and 4T1/RBP4 tumor cell lysates), and we did not observed significant differences between wild-type or empty vector-transduced cell lines and Rbp4-transduced cells (Figure S8A–C).