It has been reported that miR-9 is downregulated in gastric carcinoma and it has tumor suppressor activity by NF-κB1 expression regulation [10, 19], we reasoned that hypermethylation of CpG islands located in the promoter of one or more miR-9 genomic loci in cancerous tissue might be responsible. The gene discussed is NFKB1; the disease is neoplasm.