That depends. Typically, the more the cells expand during manufacturing, the more they differentiate. In the case of ALLO, it seems most are effector memory (manufacturing time is ~19 days and there are a number of steps involved). LYEL refer to this as the expansion/quality paradox. With Epi-R, they have shown they can expand TCR-T cells up to 18 billion by day ten. In addition, these cells are over 94% viable and maintain their ''stem-like'' qualities.