IGFBP4 and neoplasm: Tumours transfected with pCMV-dBP4 took significantly longer to reach an MTD of 17 mm (41.7±2.2 days) than mice-bearing tumours transfected with pCMV (32±5.9 days) or pCMV-BP4 (32.6±2.5 days) (Figure 3D).