ITIH4 and hydrops fetalis: Despite extensive arrays of in vitro functions proposed for TRP120 (former gp120) for E. chaffeensis infection of macrophages (Yu et al., 2000; Luo et al., 2011; Zhu et al., 2011; Dunphy et al., 2013, 2014), the gene encoding HF strain TRP120 homolog had the insertion near 5′ end, implicating this gene is dispensable for Ehrlichia HF infection of macrophages.