A recent study by Corr et al (2015) demonstrating that K5+ ovarian cancer cells were more resistant to cisplatin-induced apoptosis than K5- cells has suggested that K5 is a marker of a chemoresistant subpopulation of ovarian cancer cells . Their observation that the number of K5+ cells increased following cisplatin treatment agrees with the carboplatin data presented in our study. We additionally showed that K5 and K5/6 immunostaining is significantly increased following neoadjuvant chemotherapy treatment and that KRT5 mRNA is increased in chemoresistant compared to chemosensitive serous primary ovarian cancer. These findings support the notion that K5 plays an important role in the development chemotherapy resistance.