TLR7 and legionellosis: Interestingly, however, we observed a strong reduction in Ifnb expression and in production of the IFN-dependent cytokine IP-10 in cells from homozygous HAQ TMEM173/STING carriers as compared to cells from WT allele carriers in response to cGAMP, synthetic DNA, Legionella infection, and bacterial DNA, but not following stimulation with the TLR7/8 agonist Resiquimod (R848) (Fig 3A, S5A and S6 Figs).