Artwork from Furtek SL, Backos DS, Matheson CJ, Reigan P, Strategies and approaches of targeting STAT3 for cancer treatment, ACS Chem Biol. 11(2): 308-18 (https://pubs.acs.org/doi/10.1021/acschembio.5b00945). Signal transducer and activator of transcription 3 (STAT3) is a transcription factor that regulates the expression of genes related to cell cycle, cell survival, and immune response associated with cancer progression and malignancy in a number of cancer types. Once activated, STAT3 forms a homodimer and translocates to the nucleus where it binds DNA promoting the translation of target genes associated with antiapoptosis, angiogenesis, and invasion/migration. In normal cells, levels of activated STAT3 remain transient; however, STAT3 remains constitutively active in approximately 70% of human solid tumors.