IGHE and neoplasm: Therefore, in conclusion, while this study provides in vivo evidence that tumor antigen–targeting IgG2a is superior to its IgG1 and IgE homologs in controlling the tumor growth in a therapeutic setting in wild-type C57BL/6 mice, future studies may have to dissect how these different isotypes influence immune cell influx into tumors and gauge their capacity to influence the immunosuppressive microenvironment within tumors.