Selective estrogen receptor modulator (SERM) is designated as synthetic ligands 
for estrogen receptors (ERs), exhibiting tissue-specific 
agonisitic/antagonisitic activities. Among SERM, raloxifen is a most clinically 
successful as an anti-oseteoporotic agent. Such tissue-specific actions of SERM 
are presumed to mediate through unusual structure alteration of liganded ERs 
coupled with co-regulator recruitments.