Two control cell lines were utilized: RBL-SX-38, a rat basophilic line which expresses all three chains of the human FcεRI (a gift of Dr. Jean P. Kinet, Harvard Medical School [47]; and KU812, a human line established from a myeloid leukemia [48] (Figure 2B). This evidence concerns the gene FCER1A and myeloid leukemia.