ATR and neoplasm: (i) Compound (20) exerted inhibition of ATR immunoprecipitated from HeLa nuclear (IC50 of 5 nM); (ii) Compound (20) induced ATR guided phosphorylation of Chk1 (IC50 = 50 Nm, HT29 colorectal tumour cells; (iii) Compound (20) manifested selectivity towards ATR kinase; (iv) AZ20 (20) exhibited substantial mouse free drug exposure; (v) Compound (20) exerted remarkable inhibition in the tumour growth in Lovo xenografts (Figure 15).316