To determine whether tumor-draining lymph nodes from patients with breast cancer are different immunologically than lymph nodes from control individuals, we initially analyzed one SLN and one ALN from each of 29 breast cancer patients (training set, Table 1) by IHC for CD4 T cell, CD8 T cell, and CD1a dendritic cell populations (Figure 1). Here, CD1A is linked to breast carcinoma.