图 1. IL-21在根尖肉芽肿和根尖囊肿中均有阳性表达，而在阴性对照组和牙龈组织中无阳性表达 DAB.

Fig 1 Presence of IL-21-positive cells in periapical granulomas and radicular cysts, and no expression in negative group and healthy gingival tissues DAB

A：根尖肉芽肿，× 40；B：根尖囊肿，× 40；C：阴性对照，× 40；D：正常牙龈组织，× 20。箭头示阳性表达。