Concerning the localization of steroids in centrioles and basal bodies by immunofluorescence

Specific steroid antibodies, by the immunofluorescence technique, regularly reveal fluorescent centrioles and cilia-bearing basal bodies in target and nontarget cells. Although the precise identity of the immunoreactive steroid substance has not yet been established, it seems noteworthy that exogenous steroids can be vitally concentrated by centrioles, perhaps by exchange with steroids already present at this level. This unexpected localization suggests that steroids may affect cell growth and differentiation in some way different from the two-step receptor mechanism.