SV2B and oligodendroglioma: Further comparison of the level of latent splicing in oligodendroglioma Grades II and III, which represent different aggressiveness stages of the same malignant tumor, showed that in 125 gene transcripts the level of relative activation of latent splicing increased with the severity of the disease, reaching higher level of almost two orders of magnitude in TBR1 and SV2B (Figure 5C).