IGF1R and urinary bladder carcinoma: However, IGFBP5 mRNA levels in bladder cancer samples and cell lines were negatively correlated with the activation of INSR/IGF1R, and in cell lines with the anti-proliferative efficacy of an IGF1R tyrosine kinase inhibitor, suggesting that IGFBP5 over-expression in MIBC might be a useful marker of non-sensitivity to IGF1R inhibitor.