ESR1 and breast cancer: The study of Cook [84] has shown that CQ addition augmented the sensitivity of breast cancer cells resistant to endocrine therapies to estrogen receptor-α (ERα)-targeted agents Tamoxifen or Faslodex both in vitro (in MCF7-RR, LCC9, and ZR-75-1/ICI-R cells) and in vivo (in mice xenograft models), with this effect linked with alterations in immune response.