Our microarray analysis, demonstrating perforin 1 and granzyme B to be the most significantly upregulated genes in PBMC from TB-IRIS patients, compared with non-IRIS controls, and further validation of these results with RT-PCR, ELISA, and ELISPOT, highlights a role for the granule–exocytosis pathway in TB-IRIS. Here, PRF1 is linked to tuberculosis.