FZD9 and neoplasm: Frizzled-9 (Fzd9) plays crucial roles in brain development, neuromuscular junction assembly, new bone formation, and tumor suppression (Winn et al., 2005; Zhao et al., 2005; Albers et al., 2011; Avasarala et al., 2013b; Heilmann et al., 2013; Aviles et al., 2014; Ramírez et al., 2016).