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 tenosynovitis.