TYMS and systemic lupus erythematosus: Less is known about the contribution of TYMS polymorphisms to the DNA methylation levels, even if the TYMS 28-bp tandem repeat polymorphism was associated with gene-specific methylation levels in the blood DNA of patients systemic lupus erythematosus [44], and other TYMS polymorphisms were linked to either global or gene-specific methylation levels in both healthy and cancerous tissues, reinforcing the evidence that DNA synthesis and methylation are interconnected pathways [17,45,46,47].