Motifs in bipartite networks

Question

[The Last Word]

Hi,

I was looking to check if SIM (simple input motifs) motifs were over expressed in my directed bipartite network (transcription factors and genes).Since it is a directed network, I was only expecting to find motifs of transcription factors regulating genes.

However, I was surprised to see motifs of this kind too (though not in significant numbers when compared to random networks)

Can somebody help me with an explanation as to why there are motifs showing genes regulating Transcription factors in a directed bipartite network. Any help is appreciated