The ex vivo cell and gene therapy medicine field has entered into a new era driven by the registration of the first autologous products, namely Kymriah (Novartis, 2017, U.S.), Yescarta (Kite/Gilead, 2017, U.S.), and Strimvelis (GSK/Orchard, 2016, Europe). Despite this very promising context, cell-based processes are far from being mature from an industrial perspective. One proof is the frequent news of quality issues (out-of-specification) on cell therapy products.