YY1 and neoplasm: As a tumor suppressor, the transcriptional regulatory factor p53 can induce apoptosis and inhibit tumor development by regulating the expression of factors such as the pro-apoptotic protein Bax and antiapoptotic protein Bcl-2.[87] Guan et al[42] proposed that quercetin competes with p53 for the binding site of Yin Yang 1 (YY1) by binding to the multifunctional transcription factor YY1 protein, thereby disrupting the interaction of YY1-p53 and promoting the activation of p53.