MSLN and neoplasm: Analysis of her tumor tissue had strong MSLN expression (84%), CD3 positive (46%) infiltrating lymphocytes, but PD-L1 expression was relatively weak about 9% (figure 2), By fluorescent multiplex staining, CD3/PD-1 double staining showed an average 0.09% positive, CD8/PD-1 double staining was average 0.13% positive (online supplemental figure 2).