ESR2 and pachyonychia congenita: The high variability of ERbeta subtype levels in normal, preneoplastic, and cancerous prostatic cells, including Rv1 ([19] and the data shown here), coupled to the different behavior of selective ERbeta agonists on PC cell functions (as appears from our studies), strongly suggests that a careful assessment of the expression pattern of the ERbeta subtypes should not be disregarded, when considering ERbeta-targeted new drugs for PC chemoprevention.