  Genes communicate with each other through different regulatory effects, which
lead to the emergence of complex structures in cells, and such structures are
expected to be different for normal and cancerous cells. To study breast cancer
differences, we have investigated the Gene Regulatory Network (GRN) of cells as
inferred from RNA-sequencing data. The GRN is a signed weighted network
corresponding to the inductive or inhibitory interactions. Here we focus on a
particular of motifs in the GRN, the triangles, which are imbalanced if the
number of negative interactions are odd. By studying the stability of
imbalanced triangles in the GRN, we show that the network of cancerous cells
has fewer imbalanced triangles compared to normal. Moreover, in the normal
cells, imbalanced triangles are isolated from the main part of the network,
while such motifs are part of the network's giant component in cancerous cells.
Our result demonstrates that due to genes' collective behavior the complex
structures are different in cancerous cells from those in normal ones.
