The present invention relates to a ball spacer and the rolling device using it. The elastic component is provided with extended arms on both ends, one end pressing the bent bar and the other end being inserted into a hole of the box, thereby simplifying the production procedure and allowing box cover to be lifted automatically. Thus, even when a large number of information signals are transmitted in a same frequency band, these signals can be separated and demodulated satisfactorily on the receiving side. The PN junction region has a junction breakdown voltage lower than that of a PN junction region of a semiconductor element to be protected. Also described are methods for detecting modulators of the E-selectin gene using said transgenic non-human animal, and cultured cells obtained therefrom.