BMPR2 and autoimmune pulmonary alveolar proteinosis: Other frequently detected autoAbs in aPAP patient sera recognized extracellular proteins important for cellular processes, such as interleukin-10 receptor subunit beta (IL10RB) [91], C-X-C motif chemokine ligand 12 (CXCL12) [92], and bone morphogenetic protein receptor type II (BMPR2) [93].