Distribute the A to the B and the b, then the a to the B and the b. You should get four different possible combinations: AB Ab aB ab. These would then be used to set up one side of a punnett square, and the other parent's genotype would be set up the same, then put on the other side of the punnett square.
Cancer is a mutation of multiple cells through the cell cycle. cancer doesn’t only effect one cell, but effects many