ABAT and hepatocellular carcinoma: Figure 7B shows the effect of copy number variation on ABAT gene expression. Compared to diploid, shallow deletion was associated with low expression of ABAT (P < 0.001). Gene mutation is an important factor affecting gene expression and our results revealed that the proportion of ABAT gene mutation in HCC was 1%, which was related to low ABAT expression (P < 0.001) (Figures 7C, D).