VSIR and mesothelioma: Specific expression of VISTA on tumor cells measured by IHC regardless of tumor type ranges from 0 to 18% of tumor samples in most reports, with the highest percentage in mesothelioma (~90%), ovarian cancer (up to 28%), NSCLC (up to 20%), HCC (up to 16%) colon cancer (up to 15%), triple-negative breast cancer (11% to 18.5%) and gastric cancer (up to 9%) (31, 40, 45, 48–52).