Fig. 4From: External quality assessment (EQA) program for the immunohistochemical detection of ER, PR and Ki-67 in breast cancer: results of an interlaboratory reproducibility ring study in ChinaInterpretation of ER, PR, and Ki-67 immunostaining results in 41 PCs. a The misclassification rate compared to the reference values (Total N° of misclassified slides). b The misclassifications cases compared to the reference values. PCs: participant centresBack to article page