Consistently, late‐generation (G3 and beyond) TERT (Rudolph et al., 1999) or TERC‐deficient mice (TERT−/− and TERC−/−, respectively) are short living and show reduced fertility, early alopecia, kyphosis, anemia, and lymphopenia (Wong et al., 2003). This evidence concerns the gene TERC and lymphopenia.