ISG15 and neoplasm: In agreement with the first microarray study, the ISG15 transcript was increased in Ta tumours (1.4-fold, P=5.00E−05), in T1 tumours (1.7-fold, P=4.14E-08), and to the greatest extent in T2–T4 tumours (2.0-fold, P=4.12E-13) compared to normal bladder.