KITLG and infection: Infection at an MOI of 1 produced peak mean levels of 2-LTR circles, relative to the single copy gene, of 0.002 copies with no cytokines, 0.02 with FLT3L, 0.08 copies with SCF, 0.001 copies with TPO, and 0.05 copies with all 3 cytokines combined.