Other AS events related to chromosome instability occurring in HCC include exon 4 deletion (MAD1beta) in the mitotic arrest deficient 1 (MAD1) gene [136] and exon 6 deletion (AURKB-Sv2) in the serine/threonine kinase Aurora B (AURKB) [137]. The gene discussed is AURKB; the disease is hepatocellular carcinoma.