CD8A and neoplasm: Given that we did not identify higher TILs in ARID1A mutant cases at the histological level, and also found no differences in the total quantifications of various immune subpopulations assessed through multiplex immunofluorescence, we sought to further clarify if there was any difference in the spatial locations of cytotoxic T-lymphocyte subpopulations that mediate tumour cell killing (dual positive CD4 + CD8 + cells) between ARID1A mutant and wild-type cases.