The high expression of TCII-R in solid cancer cells was demonstrated using TCII-R immune-histological assessments and CD320 RT-qPCR analyses [81,82], and using radiolabeled cobalamin or analogs to label tumors [4,22,83,84,85,86], suggesting that the level of cobalamin uptake is associated to cancer aggressiveness [4]. Here, CD320 is linked to cancer.