Single-nucleotide polymorphisms (SNPs) in TLR2, TLR4, and HSP70 genes, which lead to variations in immune response and alter susceptibility to various infectious diseases, were analyzed in the Tamil-speaking Dravidian ethnic group in India, and the prevalence of the TLR4D299G SNP was found to be significantly higher in patients with scrub typhus than in controls [30]. Here, TLR4 is linked to scrub typhus.