Of the four samples, staining for peripheral lymph node addressin (PNAd), important for lymphocyte homing, was positive in tumor samples 19-36 (the source of BOC-36, Table 2) and 21-73 (the source of BOC-73, Table 2), suggesting possible TLS formation in these two cases (Figure 2D). The gene discussed is NTAN1; the disease is neoplasm.