Figure 2A demonstrates a schematic diagram of the characteristic structures of the skin and HFs in this undifferentiated stage. The epidermis and dermis of skin were sharply demarcated, and basal epidermal cells were in a uniform layer. No morphological signs or molecular distinction patterns of HF were recognized in the skin (Figures 2B,C). Only LEF1 was strongly expressed in epidermal keratinocytes in the basal and suprabasal cell layers of the epidermis (Figure 2D). The gene discussed is LEF1; the disease is hydrops fetalis.