Ekspresi CTLA-4 pada Diffuse Large B-Cell Lymphoma Subtipe Germinal Center B-cell-like dan Non-Germinal Center B-cell-like Sebagai Penanda Prognostik Dan Potensi Imunoterapi = Expression of CTLA-4 in Diffuse Large B-Cell Lymphoma Germinal Center B-cell-like and Non-Germinal Center B-cell-like Subtypes as Prognostic and Potential Immunotherapy Markers