The recent findings showing that (1) CD153 is an essential molecule for T cell-dependent control of Mtb in the mouse lung7 and (2) BCG-specific T cells induced in response to intravenous BCG immunization (mediating a durable protection against Mtb) are enriched in CD153 in non-human primates (NHP)8 prompted us to investigate the relationship between CD153 expression by Mtb-specific CD4 T cells and TB disease severity in humans. Here, CD4 is linked to tuberculosis.