ESR1 and breast cancer: This proposed link between ClpP protein expression and ClpP agonist sensitivity needs to be further investigated, as the ClpP protein expression level does not appear to be correlated with sensitivity to ClpP agonists in 17 breast cancer cell lines with different subtypes (3 ER+, 1 ER+/HER2+, 3 HER2+, 5 TNBC Basal A, and 4 TNBC Basal B) in our study [58].