In total, 30 OCCCs were assessed (13 ARID1A mutant and 17 ARID1A wild-type) with antibodies against CD4 (T-helper cells and regulatory T cells), FOXP3 (regulatory T cells), CD8 (cytotoxic T cells), CD68 (monocyte and/macrophage cells), PD-L1 and PanCK (Pan Cytokeratin, which stains tumour cells) (Figure 1) and quantified using a custom algorithm developed in the inFormTM image analysis software package (see methods). Here, CD4 is linked to neoplasm.