The MAPK/ERK pathway facilitates regulatory influence on gene expression through recruitment of downstream transcription factors—it is known that melatonin can regulate the activity of the c–Jun N–terminal kinases (JNKs) and the transcription factor c–Jun in traumatically injured mouse brains (Rehman et al., 2019), and possibly in breast cancer cells (Chan et al., 2002). This evidence concerns the gene JUN and breast cancer.