ATG14 and breast cancer: To validate these observations in a second BC model, we knocked out FIP200, ATG14 and ATG7 in MCF-7 cells, derived from a PIK3CAE545K mutant HR+/Her2− BC patient.56 In line with the results from T47D breast cancer cells, autophagy-deficient MCF-7 cells showed strongly diminished clonogenic growth and increased apoptosis when treated with DCA/Metformin.