Analysis of FOXP1 isoforms in DLBCL cell lines and nonmalignant B cells. (A) RT-PCR detection of FOXP1 isoforms in DLBCL cell lines. NTC indicates no template control. Actin was included as a control for cDNA quality. (B) RT-PCR detection of FOXP1 isoforms 9 and 3 in naive and activated (IgM, IL-2/SAC) peripheral blood B cells. (C) Western blotting detection of FOXP1 expression in the OCI-Ly3 cell line as a positive control and in naive and activated (IgM, IL-2/SAC) peripheral blood B cells using the JC12 monoclonal antibody. Blots were reprobed with antiactin as a loading control.