Immunoblotting analysis was performed to confirm the expression of several proteins identified in protein microarrays by using the rest of the total protein extracted for the microarray procedure. Protein from control B-lymphocyte extracts was loaded twice (normal tonsil) on each side of the gel. The nitrocellulose blots were probed with monoclonal anti-RCC1, p43/EMAPII precursor, procaspase-7, inhibitor 2, Hsp90, AKAP149, cyclin D1, Rb2, and procaspase-8. Loading control was performed with antiactin antibody (bottom row).