The present invention provides nucleic acid and protein sequences for a novel estrogen-regulated unconventional myosin protein, as well as methods for using the sequences for modulating the effects of estrogen in mammalian cells, methods of detecting estrogen signaling in cells, and methods of identifying compounds capable of acting as an estrogen receptor agonist or antagonist. The retainer ring includes a plurality of substantially linear segments disposed about the first member. The information processing device repeatedly estimates a center position of a spherical body having a curved surface which is estimated based on end point positions of the detected magnetic vectors. The system then determines the effect of placing an assist feature using the first value and the second value.