Advances in Immunology, Volume 138, the latest in a long-established and highly respected publication, presents current developments and comprehensive reviews in immunology. Articles address the wide range of topics that comprise immunology, with this release including chapters on Eosinophil Development, Disease Involvement, and Therapeutic Suppression, Immunoglobulin A responses to the microbiota, Unexpected roles for intracellular complement in the regulation of TH1 responses, Magnesium in T cell signaling, and immunological synapse and T cell signaling.