FLT4 and lymphopenia: As previously described (48), K14-VEGFR3-Ig mice show a moderate lymphopenia compared to littermate WT mice (percentage of T cells over live cells in WT naïve: 37.26 ± 7.67%; vs. TG naïve: 19.69 ± 4.96%; ChiSq: 14.746, mean ranks: 5.00/15.50, p = 1e-04) (Figure 7A).