IGHE and neoplasm: Furthermore, an IgE-trastuzumab was able to directly affect tumour cell viability in the absence of effector cells, putting it on par with IgG-trastuzumab, and lending support to the notion that anti-tumour IgE antibodies are as capable as, if not more than, IgG-based therapeutics in delivering direct blockade of cancer growth and survival signals [18].