STAT3 and infection: IL-10 receptor engagement leads to activation of the transcription factor signal transducer activator of transcription 3 (STAT3), which suppresses diverse cellular responses through both transcriptional and posttranscriptional mechanisms.8,9 At high infectious doses, IL-10 serves a beneficial role by improving host survival during S. pneumoniae infection.10 However, in the context of sublethal infection, IL-10 contributes to pathogen persistence.11 IL-10 is produced by several immune cell types in the lungs during S. pneumoniae infection10–12.