Fig. 4.

Safety of the expression of CRISPR/Cas9 system. a Representative hematoxylin-eosin staining and CD45⁺ IHC of liver sections from 8–10-week-old PH1 animals sacrificed 4 months after treatment with saline (n = 7), Cas9 (n = 6), Hao1-g1 (n = 6) and Hao1-g2 (n = 5). Scale bar: 200 μm. b Quantification of CD45⁺ areas (%) of liver sections. (c, d) Serum ALT (U/L) (c) and bilirubin (mg/dL) (d) levels measured in animals sacrificed 6 months after treatment. Mean ± SEM of data are presented. Kruskal–Wallis test revealed no significant differences between groups. Dotted lines represent the range of normal reference values for ALT and bilirubin serum levels