KLRK1 and hydrops fetalis: Notably, quantitative immunohistomorphoemtry (qIHM) also showed that protein expression of the immunoinhibitory HF-IP guardians, TGF-β1 and α-MSH (Gilhar et al., 2012; Bertolini et al., 2020; Paus et al., 2018; Ito et al., 2004), almost disappeared in the epithelium of HFs co-cultured with autologous ILC1lc or CD8+/NKG2D+ cells (=positive control) (Figure 5G, H and I), while these critical HF-IP guardians were still prominently expressed in negative control HFs (Figure 5G, H and I).