iNKT cells express estrogen receptor-α (ER-α) mRNA. Liver mononuclear cells were isolated from 8-week-old female mice, and αβ-TCR⁺ CD1d/α-GalCer-tetramer⁺ (iNKT cells) cells were sorted using a FACS Vantage sorter. Purity was more than 98% after reanalysis. Total cellular RNA was extracted and subjected to RT-PCR using specific primers for ER-α (40 cycles) and β-actin (30 cycles). RNAs from uterine extracts of C57BL/6 wild-type and ER-α^-/- mice were used as positive and negative controls, respectively. bp indicates base pair.