A strong IFNG response and transcriptional signatures associated with NK cell activation and cytotoxicity were closely associated with C. trachomatis infection and active trachoma in a West African population (Natividad et al., 2010), and infiltrates suggestive of NK cells were identified in scarred conjunctival biopsy tissue from individuals with trachomatous trichiasis from Tanzania (Hu et al., 2016). This evidence concerns the gene IFNG and inclusion conjunctivitis.