Concomitantly, scientists have successfully proved the efficacy of PROTACs against the following TFs in the context of cancer: nuclear factor-κB (NF-κB),559 androgen receptor (AR),560 estrogen receptor (ER),561 c-MYC,562 p53,563 STAT3,564 STAT5,565 and SMAD3.566 In addition to targeting the TFs, PROTACS have also been developed against transcription co-activators with an aim to indirectly regulate TF-associated disease phenotypes. The gene discussed is ESR1; the disease is cancer.