It has been reported that HMOX2 rs1051308 (G554A) SNP is associated with the risk of essential tremors (18) and multiple sclerosis (19), while HMOX2 rs2270363 (A-42G) SNP is related to the risk of schizophrenia (20) and age-related macular degeneration (21). This evidence concerns the gene HMOX2 and multiple sclerosis.