BTKO mice are runted compared with control littermates. (Top left) Representative image of control (Ctrl) and BTKO mice at 17 weeks of age. (Top right) Mice (male controls, n = 13; all others, n = 10) were weighed weekly, and both total body length (nose to anus) (bottom left) and femur length (bottom right) of the same animals were measured upon sacrificing. P-values: *< 0.05, **< 0.01, ***< 0.001.