The expression of TCF7 seemed to be “shut off” around birth in non-lymphoid tissues [20], while TCF7 was over-expressed in malignant tumors, e.g. colorectal cancers [21], prostate cancers [22], or breast cancers [23], in addition to lymphomas and leukemia derived from T lymphocyte [19, 24]. The gene discussed is TCF7; the disease is breast cancer.