Canonical and noncanonical pathways of NF-κB signaling are activated in AML1-deficient cells. (A) Immunofluorescent staining of p65 in c-kit + BM cells transduced with CreER or mock from AML1 flox/flox (f/f) mice with or without BMS-345541 (1μM). Scale bar represents 10 μm. Blue indicates TO-PRO3 (nucleus), and red indicates p65. The mean intensity of nuclear localized p65 was quantified with ImageJ Version 1.41o software.31 (B) Fractionated Western blotting of p65 in c-kit + BM cells of AML1-deficient (AML1 f/f Mx+), or control (AML1 f/f Mx−) mice. (C) NFKB2 mRNA expression in BM cells transduced with CreER or mock from AML1 f/f mice 48 hours after 4-OHT addition. Error bars show mean ± SEM (D) Western blotting of NFKB2 (p100 or p52) in B220 + spleen cells from AML1 cKO mice (AML1 f/f Mx+) or control mice (AML1 f/f Mx−) with or without BAFF (200 ng/mL). Protein levels were quantified with ImageJ Version 1.41o software.31