CD8A and neoplasm: We found that CD8 + cells (cytotoxic T cells) were significantly more prevalent in the stroma of the ARID1A mutant cases relative to the tumour (p = 0.0034), and this coexisted with significantly higher stromal CD68 + cells (p = 0.0007), whilst the wild-type cases showed no significant differences between the spatial location of this cell type (p = 0.0984) (Figure 4E–H).