Figure 2

Examples of immunohistochemical staining patterns of S100A2, S100A4, S100A6, S100A10 and CHI3L1 on the paediatric ependymoma tissue microarray. The tumour-specific staining pattern for S100A2 (nuclear and/or cytoplasmic) was scored as either negative (0%; A) or positive (>0%; B). For S100A4 (nuclear and cytoplasmic staining) cores were grouped as either negative/weak (<1%; C) or moderate (⩾1%; D). S100A6 and S100A10 protein expression (cytoplasmic and/or nuclear staining for A6 and membranous staining for A10, respectively) was determined based on the percentage of immunopositive cells (0%; <10%; ⩾10% and 0%; <50%; ⩾50%, respectively) ranging in intensity from negative to strong (0 to 2+). The cumulative scores denoted the expression levels, which were grouped as either negative/weak or moderate/strong for S100A6 (E, F) and S100A10 (G, H). CHI3L1 expression (cytoplasmic, granular) was scored as either negative (0%), weak (<25%; I) or strong (⩾25%; J). Magnification × 100 for all figures except h, which is × 10.