FCER1A and cancer: When bound via their Fc domains to human FcεRI-expressing rat basophilic RBL-SX38 cells, all three IgE antibodies triggered significant cell degranulation (measured by β-hexosaminidase release) in the presence of hHER2-expressing SKBR3 (Herceptest 3 +) and JIMT-1 (Herceptest 2 +) cancer cells.