Spontaneous Regression of Friend Virus Induced Leukemia: Coinfection with Regressing and Conventional Strains of Virus

Abstract

Mixtures of friend virus (CFV) and the regressing strain of friend virus (RFV) induce leukemia which regresses. The dominance of the regressing phenotype is solely a function of a threshold dose of RFV. The minimum amount of RFV which induced regression of CFV leukemia is below the titer for induction of friend disease, but does correlate ith the titer of lymphocytic leukemia (helper) activity in the these stocks.