Two ovarian cancer cell lines that express matriptase, OCAR3 and OV2008, were also studied and revealed identical characteristics with respect to matriptase activation induced by exposure to pH 6.0 buffer with the rapid formation of activated matriptase-HAI-1 complexes, which were depleted by the mAb M69 (Fig. 5A). The gene discussed is SPINT1; the disease is ovarian cancer.