Novel developments include restoring the HF immune privilege through local manipulation of the microenvironment, such as neutralizing IFNγ and providing αMSH/TGFβ1/IL10 (Paus 2020; Bertolini et al. 2020), or JAK inhibitors including ruxolitinib, tofacitinib and baricitinib to attenuate the immune attack (Pratt et al. 2017; Gilhar et al. 2019). The gene discussed is TGFB1; the disease is hydrops fetalis.