The PPARG2 Pro12Ala polymorphism (rs1801282; chr3:12351626) is a coding and missense variant where a C (common) allele is replaced by a G (minor) allele, which leads to a substitution of proline (Pro) with alanine (Ala) in the 12th amino acid from the N-terminal end of PPARG2. This attenuates (−30%) PPARG2 activity and decreases the risk of type 2 diabetes and colorectal and breast cancers [13,14,15]. Here, PPARG is linked to breast cancer.