Clonal stable CHO cell line constitutively expressing full length human CD19 protein (also known as CVID3, Genbank accession #NM_001770) and human CD20 protein (also known as MS4A1 and FMC7, Genbank accession #NM_021950). This cell line was derived from our CHO-K1 Luciferase cells (BPS Bioscience, #79725), therefore it also constitutively expresses the firefly luciferase reporter. Surface expression of CD19 and CD20 were confirmed by flow cytometry.