We have also identified that the tumors from patients with treatment-resistant disease possessed lower relative proportions of DN B cells, activated B cells, and a highly heterogeneous group of phenotypically naive cells in association with significantly increased CEACAM1 expression on the same cell subsets relative to that observed in treatment-naive melanoma patients; this suggests that the decreased cell numbers may inversely be related to CEACAM1 expression. This evidence concerns the gene CEACAM1 and melanoma.