Apart from the known PD genes (for example SNCA, LRRK2, MAPT), a new locus 4p15/bone marrow stromal cell antigen‐1 (BST1) was identified to participate in the PD progression.7 BST1, also known as CD157, plays a role in immune responses.8 In addition, BST1 could produce cyclic ADP‐ribose involved in regulating calcium homeostasis.9, 10 Either abnormal immune responses5 or imbalance of calcium homeostasis11, 12 could cause the development of PD. The gene discussed is MAPT; the disease is Parkinson disease.