NR3C1 and rheumatoid arthritis: In this context, long-term indices of HPA axis activity, as measured by means of cortisol in hair, together with dynamic functional assays to assess GC sensitivity (that is, GR number, affinity of the GR receptor, and GR-mediated gene transcription) are promising techniques to unravel further the role of GCs and the precise contribution to pregnancy-associated alterations in disease activity in RA.