CDKN2A and neoplasm: For example, EBNA3A and 3C repress the transcription of p14ARF and p16INK4A (that are CDK inhibitors that block cell cycling), thereby promoting the proliferation of infected B cells.39 Conversely, EBNA3B is not only not required for B-cell transformation; it is in fact a tumor suppressor.40 Notably, the sequences of the EBNA3s differ between EBV-1 and EBV-2.41