INS and Insulin resistance: Whilst there is inconsistency as to which component of the insulin-mediated glycolytic pathway is affected in GCs in women with PCOS, excessive serine phosphorylation has been attributed to the post-binding defect and insulin resistance observed in these women (Prelevic, 1997; Shulman, 2000; Poretsky et al., 2001; Seto-Young et al., 2003).