SERPINB2 and neoplasm: Immunostaining of tumor xenografts derived from NSG mice (MDA-MB-231 cells) or Balb/C mice (4T1 cells) that were implanted in the mammary fat pads with Kindlin-2-deficient (K2-KO) or either control (Scram) cells11,14, showed a >7-fold increase (p < 0.001) in SerpinB2 staining in the tumors derived from MDA-231-K2-KO cells (Fig. 1h, k) as well as in the tumors derived from Kindlin-2-deficient-4T1 cells (Fig. 1i, l) compared to their respective Scram controls.