Because NK cells, with a confusing role in asthma as reported, (Haspeslagh et al. 2018), make up a very small proportion of the CD45+ cells in the lung,and what is more, VISTA has low expression on NK cells (ElTanbouly et al. 2020), we speculate that NK cells may not the vital cell type that mediating VISTA's function. Here, PTPRC is linked to asthma.