A method of providing a cryopreserved treated mononuclear cell product comprising: a) Diluting a mononuclear cell product with a diluting solution, wherein said mononuclear cell product has been obtained by separating whole blood into red blood cells, plasma and mononuclear cells in a separation device, with platelets being present with either the red blood cells or the plasma, and harvesting the mononuclear cells; b) combining a mononuclear cell product with a photoactive compound that is activated by exposure to light of a selected wavelength, wherein the photoactive compound is 8-methoxypsoralen, which is present in a concentration of 100-300 ng/ml in the diluted mononuclear cell product c) exposing the diluted mononuclear cell product combined with said photoactive compound to light for a selected period of time at the selected wavelength to obtain a treated mononuclear cell product comprising apoptotic cells, d) splitting the treated mononuclear cell product into several therapeutic portions, e) combining at least multiple or all of said portions of the treated mononuclear cell product with a cryopreservation medium, wherein the cryopreservation medium may be added to the treated mononuclear product before, contemporaneously with or after that a therapeutic portion thereof has been conveyed into a cryopreservation container; f) cryopreserving the therapeutic portions of said treated mononuclear cell product that are conveyed into the cryopreservation containers, and g) thawing a therapeutic portion of the cryopreserved mononuclear cell product in a cryopreservation container when needed, wherein the apoptosis trend of the treated cells is not significantly affected by the cryopreservation and subsequent thawing. a) Diluting a mononuclear cell product with a diluting solution, wherein said mononuclear cell product has been obtained by separating whole blood into red blood cells, plasma and mononuclear cells in a separation device, with platelets being present with either the red blood cells or the plasma, and harvesting the mononuclear cells; b) combining a mononuclear cell product with a photoactive compound that is activated by exposure to light of a selected wavelength, wherein the photoactive compound is 8-methoxypsoralen, which is present in a concentration of 100-300 ng/ml in the diluted mononuclear cell product c) exposing the diluted mononuclear cell product combined with said photoactive compound to light for a selected period of time at the selected wavelength to obtain a treated mononuclear cell product comprising apoptotic cells, d) splitting the treated mononuclear cell product into several therapeutic portions, e) combining at least multiple or all of said portions of the treated mononuclear cell product with a cryopreservation medium, wherein the cryopreservation medium may be added to the treated mononuclear product before, contemporaneously with or after that a therapeutic portion thereof has been conveyed into a cryopreservation container; f) cryopreserving the therapeutic portions of said treated mononuclear cell product that are conveyed into the cryopreservation containers, and g) thawing a therapeutic portion of the cryopreserved mononuclear cell product in a cryopreservation container when needed, wherein the apoptosis trend of the treated cells is not significantly affected by the cryopreservation and subsequent thawing.