In addition, CaMKIIδC upregulates the expression of class I histone deacetylase (HDAC) in HF, including HDAC1 and HDAC3, but only HDAC1 inhibitors downregulate the autophagy gene of cardiomyocytes and reduce autophagic death of cardiomyocytes (Zhang et al., 2020). This evidence concerns the gene HDAC1 and hydrops fetalis.