IGHE and neoplasm: Such attributes of the IgE class include: (1) high affinity for IgE Fc epsilon receptors (FcεRs) (2–5 orders of magnitude greater than that of IgGs for FcγRs), (2) expression of FcεRs on a distinct spectrum of tissue-resident and tumor-resident immune effector cells, (3) long tissue residency and retention of IgEs by immune effector cells, (4) lack of an inhibitory Fc receptor and (4) active immune surveillance in Th2-biased environments in tissues such as the skin and gut.