On the other hand, we observed that testing for ACPA reactivities can identify one out of four at-risk individuals, with less need of specialist care for follow-up assessment, and ultrasound assessment of tenosynovitis can identify a group of individuals where 9 out of 10 will progress to arthritis suggesting potential for these factors to be measured in the clinic, after further research. This evidence concerns the gene PRTN3 and arthritic joint disease.