Differential cross sections of the reactions pn → pp_{S} + π^{−} and pp → pp_{S} + π^{0} with the energy of 0.8 GeV in the region of small forward angles were discussed. Here, “ppS” denotes a proton pair with low excitation energy Epp, less than 3 MeV. It turned out that the cross section of the reaction pn → ppS + π- is almost 60 times smaller than that of the reaction pp → ppS + π0. The meaning and different interpretations of this result were considered. These data were obtained from the ANKE facility, COSY, Jülich, Germany.