Because it is hard to knockdown BP1 and DLX7 expression alone by RNA interference, we performed gain-of-function experiments in K562 cells with BP1/DLX7 overexpression by infection with lentivirus (Genechem, Shanghai, China) carrying the complete CDS of BP1 and DLX7. The establishment of K562 cells stably overexpressing BP1 was proved by both RT-qPCR (Fig. 2a, b) and western blot (Additional file 12), whereas K562 cells stably overexpressing DLX7 were only confirmed by RT-qPCR because of the lack of specific antibodies (Fig. 2c, d). Here, DLX4 is linked to infection.