The choice of preventive treatment regimen for contact persons invited to enrol is driven by factors such as the intensity of contact, the index patient's resistance profile (specifically bacteriological confirmed MDR/RR-TB or pre-XDR-TB), and the confirmation of infection with M. tuberculosis using tests like interferon-gamma release assay (IGRA), of new TB antigen-based skin tests (TBST). This evidence concerns the gene IFNG and tuberculosis.