CTLA4 and lymphoma: To evaluate our first hypothesis if the S protein binds to any cell surface receptor of cHL/FL, we performed protein–protein docking between the Spike-RBD and reported lymphoma cell surface markers (CD15, CD20, CD27, CD30, CD40, CD45, CD80, CD86, CD95, and CTLA-4/ CD152) using the ZDOCK server [30].