S100A8 and vitamin B12 deficiency: Several literature reviews have shown controversial studies related to H. pylori, ferritin and vitamin B12 deficiencies [[40], [41], [42],[44], [45], [46], [47], [48],[91], [92], [93], [94]] while few studies have explored the correlation between the oncoprotein CagA and ferritin, vitamin B12 deficiencies [43,95].