LINC02549: LINC02549, also known as Long Intergenic Protein Coding RNA 2549, is an RNA gene that belongs to the lncRNA class, which makes up a significant portion of the human transcriptome [PMC8579100]. Carriers of two copies of the LINC02549 rs7767069T allele have been found to have increased levels of soluble scavenger receptors CD5 and CD6 in their serum [PMC8579100]. These receptors are highly expressed in regulatory T cells and a specific subset of B cells [PMC8579100]. It is hypothesized that the LINC02549 rs7767069 SNP may negatively impact the response to anti-TNF drugs by stimulating the production of these soluble receptors and inducing long-term T cell-mediated immune responses [PMC8579100]. A meta-analysis showed that each copy of the LINC02549 rs7767069T allele significantly decreased improvement in DAS28 by 17% after treatment with a TNFi [PMC8579100]. This suggests that LINC02549 may play a role in modulating CD45RA+CD45RO+ T lymphocytes, which could promote inflammatory responses and hinder inflammation control during anti-TNF drug treatment [PMC8579100]. The overall linear regression analysis revealed that several SNPs, including LINC02549 rs7767069, had a significant effect on TNFi response in rheumatoid arthritis patients [PMC8579100]. The association between LINC02549 rs7767069 and poor response to TNFi was significant in two populations analyzed and remained significant after multiple testing correction [PMC8579100]. Functional experiments showed that the LINC02549 rs7767069 polymorphism correlated with increased numbers of CD45RO+CD45RA+ T cells in blood [PMC8579100]. This suggests that this genetic marker may influence TNFi response by modulating this specific T cell subset and contributing to inflammation [PMC8579100]. A recent meta-analysis confirmed the association between LINC02549 rs7767069 and a lower response to TNFi [PMC8879844].