Diet is an important contributory factor towards the development of various cancers and knowing that lymphocytes express CYP1A2 and that the food mutagen, PhIP, activated by CYP1A2, contributes in many dietary tumours (Anderson et al. 1997; Cheung et al. 2011; Voutsinas et al. 2013), we investigated for the first time in this study the effects of PhIP at basal levels as well as by co-supplementation with either myricetin bulk (MYR B) or myricetin nano (MYR N) in lymphocytes from healthy individuals and pre-cancerous, monoclonal gammopathy of unknown significance (MGUS) patients. The gene discussed is CYP1A2; the disease is cancer.