CD34 and hydrops fetalis: In addition, a large body of data shows that CD34, is uniquely expressed on murine HF bulge keratinocytes, which is also expressed in both epithelial and mesenchymal components of anagen human HFs (Ito et al., 2007; Enshell-Seijffers et al., 2010; Tsai et al., 2014; Kaur et al., 2016; Tao et al., 2019).