CD274 and classic Hodgkin lymphoma: Median expression of PD-L1 in TILs, PD-L1 in HRS cells and PD-1 in TILs were higher in the present study compared to a previous study from our research group where 387 cases with cHL were included irrespective of pre-existing rheumatic diseases (20%, 16% and 9% vs. 12%, 0% and 2%, respectively) [3].