Goswami and colleagues describe how lactylation of histone lysine residues regulates the transcriptome, metabolism and function of CD8⁺ T cells.

Some enhancers can limit their activities to specific spatial–temporal domains by enhancer suboptimization. Ou et al. find that classical dendritic cell (cDC) development depends on Irf8 suboptimization, which prevents unwanted IRF8 autoactivation in developing cDC2s while maximizing IRF8 expression in developed cDC1s.

Dolatshahi and Wessel use an in silico modeling approach to predict maternal–fetal IgG transfer selectivity and efficiency in utero that is needed for neonate protection against pathogens.

In this Review, Sarah Cobey discusses how past exposures shape B cell responses to vaccinations with influenza and SARS-CoV-2.

Goswami and colleagues describe how lactylation of histone lysine residues regulates the transcriptome, metabolism and function of CD8⁺ T cells.

Some enhancers can limit their activities to specific spatial–temporal domains by enhancer suboptimization. Ou et al. find that classical dendritic cell (cDC) development depends on Irf8 suboptimization, which prevents unwanted IRF8 autoactivation in developing cDC2s while maximizing IRF8 expression in developed cDC1s.

Misharin, Sala and colleagues show that in patients with lung fibrosis after COVID-19, monocyte-derived alveolar macrophages activate an inflammatory and fibrotic program that was similar in patients with either resolving or progressing fibrosis.

Zhou and colleagues find that GPR34 is a metabolic immune checkpoint for ILC1-mediated antitumor immunity.

This Comment discusses the explosion in innovative systems biology approaches in infectious disease studies. We outline the numerous challenges associated with these technologies from standardizing data science approaches to reproducibility of findings, as well as cost.