Suliman et al.22 attempted to reduce the number of genes in the 16-gene COR signature8, paving the way for a simplified point-of-care test, and reported a RISK4 signature (GAS6, SEPT4, CD1C and BLK) which predicted risk of TB progression on multi-cohort test sets from South Africa, The Gambia and Ethiopia (AUCs: 0.67–0.72). This evidence concerns the gene BLK and tuberculosis.