PIWIL4 and neoplasm: We identified immunostaining of tumor cells with anti-PIWIL1 antibodies in 34,6% of IBCs (n = 52) and anti-PIWIL3 antibodies in 8% of IBCs (n = 12) and absence or slight staining with anti-PIWIL2 antibody in 48,3% of IBCs (n = 67) and anti-PIWIL4 antibody in 48,6% of IBCs (n = 73) (Figure 2).