  Effects of pairing with isospin $T=0$ and $T=1$ are systematically studied in
a model, which is based on a realistic nucleon-nucleon interaction and allows
to describe the transition from infinite nuclear matter to finite nuclei.
Special attention is paid to the development of the spin-orbit term in the mean
field of nucleons in finite nuclei. The spin-orbit term yields a drastic
suppression of $T=0$ proton-neutron pairing but does not lead to a complete
disappearance in finite nuclei. Arguments are presented, why no clear evidence
of $T=0$ pairing can be observed in the binding energies of finite nuclei.
