The HER2-positive subtype had a statistically significantly higher average HER2 transcript absolute difference between adjacent tumor pseudo-cells, in comparison to Luminal B/HER2-positive tumors, indicating a higher level of spatial heterogeneity (13.3 vs. 8.7, Mann-Whitney test, P = 0.04, Supplementary Figure 7E). Here, ERBB2 is linked to neoplasm.