In a popular article it is mentioned that in centrifugal experiments with cancer cells that
When subjected to microgravity-conditions, the cancer cells were unable to sense each other and therefore had a very hard time coming together.
which is because
[...] the process through which cancer grows and spreads would seem to indicate that there is a means through which the cells are able to sense each other and gravitate together to form a tumor.
I would now be interested in the role of such fundamental forces in cell-signaling.
How does gravity interact with cell-signaling and lead to the 'gravitation' of tumor cells towards one another?
To my knowledge, cell signaling is a bunch of processes that involve the propagation of electrical signals by chemical means, so I am rather surprised that gravity would play any role in this.