Differentiating genes in primary cutaneous large B-cell lymphoma. Seventy-one statistically significant differentially expressed genes identified as most discriminating genes between primary cutaneous follicle center cell lymphoma (PCFCCL) and primary cutaneous large B-cell lymphoma of the leg (PCLBCL-leg) with fold changes of at least 3.0 were classified by biologic function. Forty-eight genes were highly expressed in the group of PCLBCL-leg, and 23 genes were up-regulated in the group of PCFCCL. Genes indicated by an asterisk (^*) were not present in the B-cell signature.²²