SOAT1 and Bartsocas-Papas syndrome 1: However, published studies suggest that nearly all HC debris is extruded from the luminal surface of BPs (Hirose et al., 2004; Warchol et al., 2012) and that little or no HC debris is detected in SCs in BPs (Warchol et al., 2012), indicating that phagocytosis of SCs may not be a mechanism for the initiation of type I IFN/JAK/STAT signaling in chick BPs.