However, in non‐malignant target tissues, the binding of PD‐L1 to PD‐1 induces the anergy, exhaustion or apoptosis to establish donor's T cell tolerance and prevent GvHD (Cassady et al., 2018; Fujiwara et al., 2014; Kitazawa et al., 2007; Saha et al., 2016). The gene discussed is CD274; the disease is graft versus host disease.