In order to determine whether or not differences at the binding/recognition step of LAK CML are associated with differences observed in the LAK susceptibility of drug sensitive and resistant paired breast cell lines, the level of surface expression of adhesion molecules ICAM-1, LFA-3, N-CAM, and CD18, as well as P-gp and HLA Class I were measured in conjunction with the LAK CML of the cell lines. The gene discussed is PGP; the disease is chronic myelogenous leukemia, BCR-ABL1 positive.