Preparation of ROALD experiment samples in the ESA laboratory in Baikonour, Kazakhstan, ahead of the BIO-4 mission to the International Space Station with the Soyuz TMA-13 spacecraft. The function of immune cells in culture is studied in the ROALD experiment (ROle of Apoptosis in Lymphocyte Depression). In microgravity it has been observed that lymphocyte activation is depressed, this experiment will assess if this is due to activation of programmed cell death (apoptosis).