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. Here, HDAC5 is linked to breast cancer.