Hello sunblok -

The PCG experiments are carried out in low Earth orbit, where the Earth's magnetic field shields the crew from most of the deadliest radiation.

The crystals of different proteins are grown so that they may be studied by X-ray defraction, and these crytals must be both very pure and uniform for this technique to be applied. This work is done so that new medicines may be developed.

According to today's data, the radiation load in both deep space and on the surface of Mars is pretty high, between 2 to 8 heavy ions PER CELL PER YEAR.
My guess is that this can be engineered around to some degree for exploration pruposes, but it pretty much rules out terra-forming Mars, as even a denser atmosphere would not be sufficient to stop that much radiation.

EP