PLEKHS1 and in situ carcinoma: PLEKHS1 expression was significantly increased in G3T1 compared to G1Ta tumours (p = <0.01), whilst IGFBP2, IGFBP4, and IGF1R were significantly reduced in the more advanced tumour group (p = <0.010.03, <0.01, respectively), which were similar results to those observed in CIS.