Thus, ER positivity, Bcl-2 positivity and p53 negativity, which co-occurred in a majority of breast cancer cases in the present analyses, all appear to be part of a more general molecular constellation that could be driven by obesity, even though more experimental insight is needed to better understand the interplay between obesity and these tumor characteristics. The gene discussed is TP53; the disease is obesity due to melanocortin 4 receptor deficiency.