DDIT3 and Bloom syndrome: When we used TUDCA to treat BLM+HSV1 mice, the BLM+HSV1+TUDCA group expressed significantly lower levels of ATF‐4 (P < 0.0001), CHOP (P = 0.0011) and ATF6 (P < 0.0001) than the BLM+HSV1 mice.