Reduced T-cell numbers and expression of T-cell immunologic synapse proteins are associated with disease transformation in FL. (A) Representative low-power (× 10 magnification) images (top panels) of CD3⁺ expression on TMA cores from pretransformation (FL) biopsies compared with the patient's disease progression/transformation (DLBCL) biopsies. Note the distinct strong interfollicular CD3⁺ expression on FL biopsy compared with weakly diffuse expression on the patient's transformed biopsy. Representative high-power (×40 magnification) images (bottom panels) of interfollicular (CD3⁺ location) Itk, Filamin-A, and Rab27A expression on FL biopsies compared with weak diffuse expression of these T-cell synapse signature proteins on the patient's transformed biopsies. Quantitative analysis of expression and percentage of positive cells for these synapse signature proteins comparing total FL biopsy core area (sum of intrafollicular and interfollicular location expression) to total DLBCL biopsy core area is shown in supplemental Figures 5–8.