Production of tumors in hamsters by cells of a pig uterine tube line.

Tumorigenicity was investigated in a pig established cell line continuously subcultured more than 400 times. Tumors were not found in hamsters' cheek pouches inoculated with cells from the first 200 subcultures. Fibroma developed in five out of 13 animals (9/26 pouches) inoculated with cells of the 313th and 314th subcultures. Two chromosome markers were found in the 290th subculture, in the 313th subculture inoculum and in tumor cells.