CD4 and tuberculosis: Interestingly, in patients with LTBI, but not healthy or BCG-vaccinated individuals, neither patients after TB treatment presented a CD4 cell subset, which is CD27−PC-1+; these data were interpreted as evidence of in vivo induced cell differentiation driven by M. tuberculosis antigens, which suggest that these membrane markers could help to differentiate individuals with LTBI from healthy individuals and help to monitor TB drug treatment (107).