LGR5 and hydrops fetalis: To verify the role of Lgr5+ cells in WIH-A, we specifically depleted Lgr5+ cells in Lgr5-Cre:R26DTR/+ mice (P56–63) via the administration of TM and DT, and the absence of Lgr5+ HF stem cells almost completely blocked WIH-A on PWD-15 (Fig. 5d,e).