Altogether, the data indicate that Nbn-deficiency in HF stem cells led to γ-H2afx accumulation, growth arrest via the induction of Trp53/Cdkn1a and Cdkn2a and a pro-inflammatory response involving Ccl2, Il6, Tnf and Il1b up-regulation. The gene discussed is CDKN1A; the disease is hydrops fetalis.