Inbr: More than F150. Albino. Genet: a, b, … Inbr: More than F150. Albino. Genet: a, b, c. Origin: Dr L. C. Strong, 1921, from a cross between the Cold Spring Harbor and Bagg albino random-bred stocks (and therefore relavted to BALB/c). Internationally distributed, Strain A was the third most widely used strain in cancer and immunology research (Festing, 1969), though its popularity has probably declined recently. Although it may be classified as a general-purpose strain, it is well known for a high susceptibility to induction of congenital cleft palate by cortisone and a high spontaneous incidence of lung adenomas, as well as developing a high incidence of lung tumours in response to carcinogens. Shimkin and Stoner (1975) suggest that this response may be used as a rapid in vivo assay for carcinogenesis. The strain also suffers from a defect in macrophage function somewhat resembling the mutant lps found in C3H/HeJ (Vogel et al 1981). t lps found in C3H/HeJ (Vogel et al 1981).