Our hypothesis is formulated based on two key observations: CD36 is downregulated in FBs of non-cancerous breast tissues with high mammographic density (MD) [10], where MD is associated with an increased breast cancer risk [11,12,13]; and normal FBs have been shown to have an anti-tumorigenic function through paracrine signaling [2,14,15]. This evidence concerns the gene CD36 and breast cancer.