AHCY and viral infectious disease: Finally, we found the functional category methylation-dependent chromatin silencing overrepresented among the down-regulated genes; two isoforms of the gene s-adenosyl-l-homocysteine hydrolase (SAHH), two adenosine kinases (ADK) and three s-adenosyl-l-methionine synthetases (SAMsynth) were repressed during viral infection.