Moreover, we also developed a novel DMXAA derivative—3-hydroxy-5-(4-hydroxybenzyl)-4-methyl-9H-xhanthen-9one (HHMX) —and tested the therapeutic potential of HHMX not only in J774 dual reporter cells expressing STING constructs with various SAVI mutations but also in PBMCs isolated from a SAVI patient with heterozygous STING N154S mutation (human counterpart of mouse N153S mutation). Here, STING1 is linked to STING-associated vasculopathy with onset in infancy.