Abstract
A continuous line of rodent cells carrying the genome of the Rous sarcoma virus was stably transformed by exposure to viable herpes simplex virus of either subtype 1 or 2. Transformation was accompanied by alteration of morphology, growth characteristics, acquisition of a thymidine kinase activity (EC 2.7.1.21) resembling the corresponding specific activity of the enzyme in the herpes simplex virus, and capacity to express continuously some antigens specific for herpes simplex virus.