All morbidly obese patients who are candidates for a bariatric procedure in the investigators institution who has a fatty liver in their routine preoperative US will undergo a fibroscan to assess the degree of liver fibrosis preoperatively in addition to a blood sample that will be withdrawn from those participants to isolate the NK cells and to assess their activities by the assessment of the active form of NK cells (CD107a) using the spectrometry (FACS) analysis.