Taking into account the presence of galectin-3 in immune cells, and the role of immune system in rheumatic diseases the purpose of our study was to assess the serum galectin-3 concentration and compare its diagnostic values with the routinely used tests between rheumatic diseases, including rheumatoid arthritis, systemic sclerosis, and systemic lupus erythematosus. This evidence concerns the gene LGALS3 and systemic lupus erythematosus.