Figure 4. (A) Relative telomere length (TL) of three tissues of humanized Nbs mice as estimated by qPCR. Relative TL (T/S ratio) in brain, heart, and liver tissues of humanized Nbs mice (Nbn-/-NBNdel, in the figure labelled Nbn-) 87, 68 and 92 (age: 32, 41, and 39 days) and humanized wild-type mice (Nbn-/-NBN+, in the figure labelled Nbn+): 95 and 98 (age: 32 days) estimated by qPCR. (B) Relative TL of an NBS fetus. Relative TL ±SD (T/S ratio) in 14 different tissues of a 32 week old NBS-fetus estimated by qPCR. Original from .