Comment on "Tumor-initiating cells establish an IL-33-TGF-β niche signaling loop to promote cancer progression".

Taniguchi et al. (Research Articles, 17 July 2020, p. 269) claim that the cytokine interleukin-33 induces accumulation of tumor-associated macrophages expressing the immunoglobulin E receptor FceRI. Although these findings hold great therapeutic promise, we provide evidence that the anti-FceRI antibody used in this study is not specific for FceRI on macrophages, which raises concerns about the validity of some of the conclusions.