[CANCER RESEARCH 36, 1735-1739, May 1976] SUMMARY Fennitins from normal adult human liver and heart were compared with femmitinsfrom a lung carcinoma metastatic to liver and from HeLa cells on the basis of their isofemmitin

Fennitins from normal adult human liver and heart were compared with femmitinsfrom a lung carcinoma metastatic to liver and from HeLa cells on the basis of their isofemmitin profiles, subunit composition, and immunological relation ships. Each femnitin preparation gave different isofemmitin profiles, but several contained common isofemnitins.All of the tumor isofemmitinshad counterparts in the normal tis sues. All femmitinscontained similar subunits but in different proportions. Qualitative differences were demonstrable in some femmitinswith antibodies to different tissue femnitins. These differences correlated with the subunit composition of the fennitins. By appropriate absorption, an antibody pop ulation was obtained that was apparently specific for one subunit type. Heart femmitingave lines of apparent identity with the tumor femmitinswith these antibodies. It is con cluded that tumor femnitinsare not tumor-specific antigens but correspond to isofemnitins in normal adult heart.