ARHGEF15 and neoplasm: The intracellular colocalization of E5 and PDGFβR indicates that this protein interaction may take place in the GA and may be another proof of evidence of the possible receptor activation upon E5 interaction; juxtanuclear colocalization of E5 with PDGFβR was also reported in bovine urinary bladder cancer by this research group, suggesting that this finding could be common in BPV-induced tumours [15].