Results of selection for affinity in cell populations of rat transplantable tumors

: Results of selection for the affinity for lung tissue in cells of three transplanted tumors of the rat are given. Tumor cell suspensions were injected intravenously-intraperitoneally or subcutaneously-intravenously (the clonal line -- clone circuit), or intravenously-intravenously (the clone-clone circuit). The efficiency of the method has been shown in the cases of the Worker carcinoma and of a 20-methylcholantren-induced rhabdosarcoma. A 10-fold recloning of cells of the ovary ascite tumor failed to increase their affinity for the lung tissue. It is suggested that a hereditary heterogeneity with the trait "the affinity for lung tissue" may be characteristic of tumor cell populations.