Aberrant expression of GSK3 proteins in primary lymphoma patient (P) cells and their proliferative response to 9-ING-41. (A) Immunoblot of GSK3α and GSK3β proteins showing overexpression in patient samples vs normal B-cell control. P1, MCL; P2, high-grade B-cell lymphoma; P3, follicular large B-cell lymphoma 3B; P4, DLBCL; and P5, angioimmunoblastic T-cell lymphoma. (B) 9-ING-41 inhibited proliferation in all 5 patient samples. (C) Immunohistochemistry staining of GSK3β on paraffin tissue sections from patients with various lymphomas (original magnification ×40). Representative images show the spectrum of GSK3β (brown) overexpression in different lymphoma samples. Methylene blue counterstaining (blue) reveals cells negative for GSK3β in the background and in the antibody negative-control panel.