Furthermore, the evidence showing that our culture system offers capabilities of both scalability and handleability is that the primary rat hepatocytes encapsulated within cell fibers increased in number while keeping not only their sensitivity sufficient to detect the toxic effects of well-known hepatotoxic compounds such as acetaminophen and diclofenac (Table 1 and Figs. S4–S7), but also their ability to secrete albumin in adequate amounts to be observed in the blood of recipient rats with analbuminemia after being transplanted into NARs (Fig. 6). Here, NARS1 is linked to congenital analbuminemia.