CFTR and Schnyder corneal dystrophy: We therefore sought to determine in SCCD a) whether there is a basal constitutive adenylyl cyclase activity driving cAMP-mediated Cl- secretion, b) whether Cl- secretion is enhanced by glucocorticoid hormones via activation of glucocorticoid receptors, c) whether Cl- secretion is mediated through PKA action and d) whether Cl- secretion is mediated by a basolateral NKCC and/or KCC and an apical CFTR Cl- channel.