Many potentially therapeutic products involve the culture of stem cells. Their commercial success depends on the development of scalable good manufacturing practice (GMP) technologies that can both robustly and cost-effectively produce very large numbers of cells. Through many improvements and innovations in bioprocessing operations over the years, fed-batch suspension culture has remained the most common mode for large-scale biopharmaceutical manufacturing. However, some recent events suggest that may be changing (1,2). For the culture and expansion of stem cells, large-format adherent…