Genes involved in endocytosis/antigen processing (SNX1, SNX2, TLR4, LAMP1) (39–42) were all found to be higher in PsA, compared to RA, which is in agreement with the impaired endocytosis observed in the RA patients, and our previous observations in in-vitro generated Mo-DC (23). This evidence concerns the gene LAMP1 and rheumatoid arthritis.