SRI and Infertility: To this regard, Manohar et al., using a 2-D gel electrophoresis–proteomic approach, showed that proteasome subunit α type-5, tubulin-polymerization-promoting protein family member 3, superoxide dismutase [Cu-Zn], and sorcin were significantly decreased in the mid-secretory phase in endometrium of infertile women, highlighting their physiological relevance in endometrial differentiation/maturation [50].