An interim analysis of a prospective breast cancer cohort currently under evaluation was presented at the 2011 AACR meeting, indicating a striking difference in the 9-month survival rate of patients with more than 450 CD4/mm3 or more than 20% diversity of their TCR repertoire (83% for CD4 >450/mm3 vs 45% for CD4 <450/mm3 and 78% for TCR diversity >20% vs 17% for TCR diversity <20%) (AACR 2011 abstract 165). This evidence concerns the gene CD4 and breast cancer.