RT-PCR amplification of cDNA with CD44 specific primers. (A) RNA prepared from resting EC and EC treated for 4, 24, and 48 hours with bFGF was amplified with 5′ and 3′ constant exon primers (CD44s) and with an exon v5 specific primer. The lane identified with “T” represents RNA from CD3 activated peripheral blood T lymphocytes, which serves as a positive control. Lanes identified with “–” represents RNA from a CD44⁻ cell line. “M” represents the molecular weight markers, which are identified on the right. (B) RNA from bFGF activated (10 ng/mL, 24 hours) is amplified with specific primers for all variant exons. The lane identified with “C” represents the amplification with 3′ and 5′ constant exon primers (CD44s).