Degree distributions. Changes in the degree distributions of breast tumor coexpression networks during the course of neoadjuvant treatment with letrozole. Coexpression networks are built from gene expression data measured at diagnosis (Pre-treatment), following 10-14 days of letrozole treatment (Mid-treatment), and following 90 days of letrozole treatment (Post-treatment). Each network contains 1044 nodes representing the set of genes differentially expressed following 90 days of letrozole treatment. The number of links vary over the course of letrozole treatment with 2262, 2242, 2858 links in the pre-treatment, mid-treatment and post-treatment graphs, respectively.