Here, Raffatellu and co-workers discuss our growing understanding of how primary bile acids (which are cholesterol-derived molecules synthesized in the liver) and secondary bile acids (which are primary bile acids that have been microbially modified) shape immune responses in health and disease, with a particular focus on bile acids and intestinal immunity.

This Review by Arnold and Munitz discusses the diverse roles of eosinophils in the settings of tissue homeostasis, infection, allergy and cancer. The authors explain the molecular mechanisms that enable eosinophils to adapt to diverse tissue types and conditions, and they consider the therapeutic potential of eosinophil-depleting drugs in the clinic.

In this Viewpoint, Nature Reviews Immunology invites eight experts in the field to share their thoughts on the key questions and challenges in MDSC research.

Here, the authors review the single-cell sequencing studies of rheumatic and allergic diseases, providing insight into disease pathogenesis, biomarkers and therapeutic targets.