IL6 and Castleman disease: Kinugawa Kinugawa Y Y Uehara Uehara T T Iwaya Iwaya M M Asaka Asaka S S Kobayashi Kobayashi S S IL-6 expression helps distinguish Castleman’s disease from IgG4-related disease in the lung IL-6 expression helps distinguish Castleman’s disease from IgG4-related disease in the lung BMC Pulm Med BMC Pulm Med 2021 2021 21 21 219 219 10.1186/s12890-021-01603-6 10.1186/s12890-021-01603-6 supplied-pmid 34246246?