Another example of the use of zebrafish larvae to uncover a host-pathogen interaction relevant to human mycobacterial infection is the recent forward genetic screen by Tobin and Ramakrishnan, who mapped a hypersusceptibility mutation to the leukotriene biosynthesis gene, lta4h, and showed that heterozygosity at the LTA4H locus correlated with susceptibility of human populations to both TB and leprosy [28]. The gene discussed is LTA4H; the disease is leprosy.