Fig. 1

Two molecularly distinct subtypes of canine mammary tumors were identified. Heatmap of the row scaled log₂(TPM) values of 1387 metagenes from 143 canine mammary tumors (columns), ordered from left to right by subtypes, PAM50 classification, and the ESR1 expression level from high to low. The metagenes (rows), identified from the NMF analysis (see Methods), are ordered by hierarchical clustering. Lymph invasion is defined as having tumor cells in peritumoral lymphatic vessels and/or regional lymph nodes. Tumor mutation burden (TMB), defined as the number of somatic base substitutions and small indels per megabase (Mb) of callable coding sequence, is obtained from a previous publication [33]. For ER/PR status, a tumor is considered “negative” or “positive” if its ESR1/PGR has a FPKM value of \(\le\) 1 or > 1, respectively. For HER2 enrichment, a sample is considered “not enriched” or “enriched” if its ERBB2 has a FPKM value of \(\le\) 35 or > 35, respectively. “Other PIK3CA” represents all non-H1047 coding mutations in PIK3CA. “No data” represents samples with no mutation data. Annotation row titles marked with a “*” indicate a significant (\(p\le 0.05)\) difference in enrichment between the subtypes