CDKN1B and pterygium: In this study, we examined the expression of Skp2 in pterygium fibroblast cells (PFC) and investigated if small interfering RNA (siRNA)-mediated gene silencing of Skp2 can be employed to inhibit protein 27 kinase inhibition protein 1 (p27kip1) down-regulation in PFC and the effects of down-regulation of p27kip1 on PFC proliferation.