Some other potential receptor candidates including an isoform of decorin involved in WAT expansion, tyrosine kinase-like orphan receptor-1 (ROR1) in 3T3-L1 cells, or insulin-like growth factor 1 receptor (IGF-1R) in fibroblasts from rheumatoid arthritis patients have also been described [83]. Here, IGF1R is linked to rheumatoid arthritis.