CD27 and infection: Analysis of T cell memory markers expressed by M.tb lysate-specific CD4 T cells showed that recent QFT conversion was associated with a decrease in KLRG-1- TSCM (CD45RA+CCR7+CD27+) and TCM (CD45RA-CCR7+CD27+) cells, and an increase in KLRG-1- TE (CD45RA-CCR7-CD27-) cells compared to the pre-infection (QFT−) time-point, indicative of increased antigen exposure (Supplementary Fig. 6a).