HDAC2 and chronic obstructive pulmonary disease: By comparing m6A methylation typing and m6A genotyping with the box diagram of HDAC family protein expression, we found that HDAC2 and HDAC4 were expressed at low levels in m6A methylation type A and m6A genotype A, while HDAC1, HDAC3 and HDAC6 were expressed at low levels in m6A methylation genotype B and m6A genotype B. Ergosterol can improve the activity of HDAC3 in macrophages and inhibit the activation of PCAF, as well as acetylate NF‐KB/p65 to intervene in the inflammatory response in COPD [48].