A Immunofluorescence showing gammaH2AX foci in Trf2F/F MEFs at the indicated time points following 4OHT treatment and consequent TRF2 knockout and treated with DMSO or ATMi. Scale bar, 25 µm. B RT-qPCR detection of Ace2 mRNA expression levels in MEFs Trf2F/F treated as in A (n = 3 independent experiments). 