Recent studies have demonstrated that PD-L1 also exists on the surface of exosomes generated by their parental tumor cells (Chen G. et al., 2018; Lubin et al., 2018; Ricklefs et al., 2018; Theodoraki et al., 2018b; Yang et al., 2018; Fan et al., 2019; Kim et al., 2019; Poggio et al., 2019; Cordonnier et al., 2020; Huang et al., 2020). Here, CD274 is linked to neoplasm.