Discuss about xeno-transplanation
Most defects / diseases treated by xeno-transplanation are not genetic in origin so the therapy will have no impact on gene pool in terms of change in frequency of defective alleles.
As Xeno transplantation involves the transplanting of organs / tissues that do not affect the gametes, it will have no impact on gene pool other than the impact of longer survival of affected people.
NOT genes from other species entering human gene pool.