Table 3.

H3K27me3 IHC staining protocols in included studies

	Study location	IHC evaluation technique	TMA sample size	Whole slide sample size	Tissue age exclusion	Oldest included tissue age (years)	Antibody dilution	Antibody incubation time	Definition of H3K27me3 loss
Ammendola et al. [4]	Italy	Whole Slides	–	4 μm sections	None	Not Reported	1:200	Not Reported	Staining absent in > 95% of tumor cells
Behling et al. [7]	Germany	TMA, Whole Slides	2 × 1 mm diameter cores	4 μm sections	None	17	1:200	Not Reported	Staining absent in all tumor cells
Gauchotte et al. [11]	France	Whole Slides	–	Not Reported	None	30	1:100	1 h	Staining absent in > 50% of tumor cells
Hua et al. [14]	China	Whole Slides	–	4 μm sections	None	Not Reported	1:100	2 h	Staining absent in > 50% of tumor cells
Hua et al. [13]	China	Whole Slides	–	Not Reported	None	13	1:700	Not Reported	Staining absent in all tumor cells
Jung et al. [15]	Republic of Korea	TMA, Whole slides	2 mm diameter cores	3 μm sections	> 5 years	5	1:100	2 h	Staining absent in > 55% of tumor cells
Katz et al. [17]	Germany, United States of America	TMA, Whole slides	2 × 2 mm diameter cores	4 μm sections	None	Not Reported	1:100	2 h	Staining absent in all tumor cells
Nassiri et al. [23]	Canada	Whole Slides	–	5 μm sections	None	21	1:200	Overnight	Staining absent in all tumor cells
Samal et al. [3]	India	TMA, Whole Slides	1–3 × 5 mm diameter cores	3–4 μm sections	None	5	1:500	2 h	Staining absent in all tumor cells