IL2 and colorectal cancer: Test the hypothesis that combination of two medicines (vactosertib and IL-2) with NK cells will be safe and will activate the donor NK cells. NK cells and vactosertib are experimental because they are not approved by the Food and Drug Administration (FDA). IL-2 (Proleukin¬Æ) has been approved by the FDA for treating other cancers, but the doses used in this study are lower than the approved doses and it is not approved to treat colorectal cancer or blood cancers.