1Interpretation of international guidelines for diagnosis and treatment of rheumatism in children (Ⅰ) : Interpretation of the EULAR/ACR classification criteria of systemic lupus erythematosusSONG Hong-meiGUIDELINES UNDERSTANDING249-2522Interpretation of international guidelines for diagnosis and treatment of rheumatism in children (Ⅱ) : Interpretation of the classification criteria of juvenile idiopathic arthritisLIU Da-wei, LIANG Fang-fang, TANG Xue-meiGUIDELINES UNDERSTANDING252-2553Interpretation of international guidelines for diagnosis and treatment of rheumatism in children (Ⅲ): The new classification criteria of idiopathic inflammatory myopathy and update on the diagnostic points of juvenile dermatomyositisHU JianGUIDELINES UNDERSTANDING255-2584Interpretation of international guidelines for diagnosis and treatment of rheumatism in children (Ⅳ) : Interpretation of diagnosis and treatment guideline for pediatric rheumatic diseases complicated with macrophage activation syndromeSUN LiGUIDELINES UNDERSTANDING259-2625Interpretation of international guidelines for diagnosis and treatment of rheumatism in children (Ⅴ) : Evaluation of the classification and diagnostic criteria of Sj(o)gren's syndrome in childhoodYU Hai-guoGUIDELINES UNDERSTANDING262-2646Interpretation of international guidelines for diagnosis and treatment of rheumatism in children (Ⅵ) : Interpretation of classification criteria of ANCA-associated vasculitis in childrenWU Xiao-chuan, XU Li-yunGUIDELINES UNDERSTANDING265-2687Interpretation of international guidelines for diagnosis and treatment of rheumatism in children (Ⅶ) : Interpretation of the classification criteria of childhood Takayasu arteritisXU Meng, LIU Jing-yue, YANG Si-ruiGUIDELINES UNDERSTANDING268-2738Interpretation of international guidelines for diagnosis and treatment of rheumatism in children (Ⅷ) : Interpretation of the classification criteria of juvenile-onset systemic sclerosis and the progress in diagnosis and treatmentZHENG Rong-jun, LU Mei-pingGUIDELINES UNDERSTANDING273-2779Interpretation of human inborn errors of immunity:2019 update on the classification from the International Union of Immunological Societies Expert CommitteeQIU Lu-yao, AN Yun-fei, ZHAO Xiao-dongGUIDELINES UNDERSTANDING278-28310Progress in the diagnosis and treatment of Behcet's syndromeHE Ting-yan, YANG JunEXPERT FORUM284-28811Clinical phenotypes of epilepsy related to CHD2 gene mutations: A report of 18 patientsCHEN Jiao-yang, ZHANG Yue-hua, ZHANG JingORIGINAL CONTRIBUTION289-294,30012Clinical analysis and literature review of 10 patients with recurrent fever and MEFV gene mutationYAN Shi, TANG Xue-mei, ZHANG YuORIGINAL CONTRIBUTION295-30013Cytomegalovirus gastroenteritis in immunocompetent children: A systematic reviewZHANG Li-yuan, LI Fu-rong, GONG Yi-ningORIGINAL CONTRIBUTION301-30614Clinical features and gene analysis of Mendelian susceptibility to mycobacterial disease due to mutations in IL-12RB1 in two childrenWEI Qi-jiao, WANG Wei, WANG Chang-yanORIGINAL CONTRIBUTION307-31015Relationship of altered platelets and coagulation biomarkers with disease activity in pediatric inflammatory bowel diseaseZHONG Yao-yao, GUAN De-xiu, MEI Tian-luORIGINAL CONTRIBUTION311-314,328 