PDCD1LG2 and diffuse large B-cell lymphoma: Additionally, PD‐1 inhibitors are considered potentially effective for high‐risk patients with less‐defined subtype DLBCL due to the activation of PD‐L1 expression and PD‐1 checkpoint pathway, the activation of JAK‐STAT signalling pathway, which can lead to PD‐1 overexpression, and the low mRNA expression of the PD‐L2 gene, the ligand for PD‐1.