PGR and neoplasm: When tumours were divided into PR+ (>10 fmol mg−1 protein) or PR− (⩽10 fmol mg−1 protein) groups there was a significantly higher level of ORβ1 (GC17) protein in PR+ tumours compared to PR− tumours (Mann–Whitney test, P=0.0268; median for PR+ tumours=55, range 5–150 and median for PR− tumours=10, range 0–75).