PCR-RFLP analysis of the cDNA derived from the EBV-LCL of H.A. cDNA fragments extending from base 200 to base 495 were enzymatically amplified from mRNA of the EBV-LCL of H.A. and normal individuals. The PCR products, both before (−) and after (+) digestion with the restriction enzyme Mbo II were analyzed on 5% polyacrylamide gel stained with ethidium bromide. Lane 1, pBR322HaeIII digest size marker; lanes 2 and 4, normal controls; lanes 3 and 5, H.A.