The present invention relates to the use of specific transporter cargo conjugate molecules for the transport of a substance of interest (cargo molecule) into white blood cells. Said transporter cargo conjugate molecules may be used for the treatment, prophylaxis, attenuation and/or amelioration of a disease and/or disorder involving white blood cells. The present invention also relates to manufacture of said transporter cargo conjugate molecules, to a method of transporting a substance of interest (cargo) into a white blood cell and to a white blood cell comprising said transporter cargo conjugate molecules or fragments thereof.