Our banner photograph of breast cancer cells: an explanation

 

This is a photograph of breast tissue from an actual human breast cancer patient. The tissue section is stained with green antibodies that detect HEXIM1 protein and orange antibodies which detect a proliferation marker Ki67 (i.e. cancerous cells). If both proteins were present in the same cells, they would be stained yellow (green plus orange) and you can see here that there are no yellow cells. This image suggests that cells which express high levels of HEXIM1 are blocked from proliferating (acting in a cancerous manner).

The implication is that if our HEXIM1 inducing drugs work, the proliferation marker Ki67 (orange) would be turned off as HEXIM1 protein levels increase in the cancerous cells when these cells differentiate and they would turn from orange to green in color.