It is important to note that 64% of patients (167 of 259) in this study had RF and/or ACPA tested clinically at one or multiple points over the course of their illness, likely to address persistent arthralgia. This is supported by the higher musculoskeletal scores (e.g., more severe symptoms) in patients with RF and/or ACPA testing compared to those without RF and ACPA testing. These limitations emphasize the need for standardized, prospective protocols in the future to assess whether these findings are generalizable to the broader PTLD population. Here, PRTN3 is linked to post-transplant lymphoproliferative disease.