selective synthesis of rf by seropositive synovium was suggested by the observation that the fractions of synthesized igm with rf activity were greater in the smc supernatants than in paired sera in all cases , and the fractions of igg with rf activity were greater in the smc supernatants of 3 of the 4 cases in which substantial amounts of igg-rf were produced .
C0039099
synovium
C0224522
smc