Expression of c-FLIP proteins in samples from patients with LGL leukemia and healthy control subjects. (A) c-FLIP Western blot analysis of whole cell lysates from a representative normal donor (control) and from 2 representative patients with LGL leukemia treated with medium alone, IL-2 (500 IU/mL), or IL-2 plus anti-Fas (APO-1) 1.0 μg/mL for 24 hours before lysis. Western blot analysis for GAPDH was performed to confirm equal loading of total protein in each lane. (B) Densitometry was performed on Western blot results from patients 8 LGL leukemia and 6 healthy control subjects to determine the average level of c-FLIP-_L and c-FLIP-_S protein expression in medium control (control), IL-2, and IL-2 plus anti-Fas (APO-1)-cultured cells. Indicated on the gel are c-FLIP-_L and c-FLIP-_S of molecular masses 55 and 28 kDa, respectively. *P ≤ .05.