MKI67 and Hernia: Other studies have acknowledged the importance of fibroblast proliferation in the formation of incisional hernias, such as the one from Franz et al.18that quantified the number of Ki-67-stained fibroblasts in cicatricial tissue from hernia sacs of rats in 3 different postoperative stages; a limitation of this study was the absence of comparison of fibroblast proliferation between rats of different ages.