A previous study further demonstrated that in the hyperhomocysteinemia mouse model and HL-7702 cells (human normal hepatic cells), homocysteine inhibited cystic fibrosis transmembrane conductance regulator (CFTR) expression, activated autophagy and induced liver injury via interaction between histone H3 lysine 27 trimethylation (H3K27me3) and DNA methylation. The gene discussed is CFTR; the disease is hyperhomocysteinemia.