GIPC1 and invasive breast carcinoma: GIPC-1 staining with 27.B1 and 27.F7 antibodies was positive only in invasive breast carcinomas (27.B1 displayed a higher reactivity rate than 27.F1) whereas GIPC-1 staining with 27.B1 and 27.F7 antibodies was negative in in situ and benign tumors (P < .001).