Other than by an aspect to your natal Mars, transiting Mars could also affect him indirectly by forming an aspect to his dispositor.
An example would be having your Mars in Aquarius, and the "Lord" of that sign, Uranus, around 9° Libra.
With transiting Mars currently in a sextile to Uranus, he would affect everything that is connected to Aquarius in that chart,
including natal Mars with his house position.
Hope this helps.