HDAC4 and breast cancer: HDAC4 and HDAC5 belong to class II HDACs, which exhibit specific roles in the progression of breast cancer.38 Elevated expression of HDAC4/5 has been observed in breast cancers, contributing to the progression and drug-resistance of cancer cells.31,39–42 The high expression of HDAC4/5 in breast cancer cells might lead to the low acetylation of SerRS that consequently decreases the nuclear translocation of SerRS and inhibits the activity of SerRS in suppressing abnormal lipogenesis.