When these cells were exposed to a pH 6.0 buffer for 20 min and lysates were prepared, a proportion of the matriptase was converted to complexes with HAI-2 in the hematological cancer cell lines (Fig 3A, lanes 2, band b) or with HAI-1 in the three carcinoma cell lines (Fig 3B, lanes 2, band c). This evidence concerns the gene SPINT1 and carcinoma.