Camkk2 deletion prevents the inhibitory effects exerted by acute activation of AMPK on downstream effectors of mTOR signaling43 and p53,31, 32 which control HSC proliferation under stress.19, 36, 37, 38, 43, 44, 45 The protein p53 is an important effector of the anti-proliferative effects of radiation and studies have shown short-term p53 inhibition following radiation damage facilitates hematopoietic recovery and prevents development of radiation-induced lymphomas.46, 47, 48 Importantly, p53 is a target of AMPK kinase. Here, MTOR is linked to lymphoma.