IL7R and immunodeficiency disease: Previous studies have shown that signaling through IL-7R is essential in the developmental process and regulation of lymphoid cells (Kondrack et al., 2003; Tan et al., 2001; Tan et al., 2002; Lenz et al., 2004; Li et al., 2003; Seddon et al., 2003), and disruption of the IL-7R signaling pathway may lead to skewed T cell distribution and cause immunodeficiency (Maraskovsky et al., 1996; Kaech et al., 2003; Carini et al., 1994).