Recently, Yokoyama et al. found that production of interleukin-6 (IL-6) and interleukin-8 (IL-8) by human GFs was enhanced significantly by the stimulation with both estrogen and progesterone at high concentrations comparable to those found in plasma of pregnant women in their study, which suggested that the capacity of female sex hormones to enhance cytokines production by human GFs has the potential to contribute to periodontal disease progression during pregnancy [48]. The gene discussed is CXCL8; the disease is periodontal disorder.