Characterizing mutational signatures in human cancer cell lines reveals episodic APOBEC mutagenesis by Petljak, M, Alexandrov, LB, Brammeld, JS, Price, S, Wedge, DC, Grossmann, S, Dawson, KJ, Ju, YS, Iorio, F, Tubio, JMC, Koh, CC, Georgakopoulos-Soares, I, Rodríguez-Martín, B, Otlu, B, O'Meara, S, Butler, AP, Menzies, A, Bhosle, SG, Raine, K, Jones, DR, Teague, JW, Beal, K, Latimer, C, O'Neill, L, Zamora, J, Anderson, E, Patel, N, Maddison, M, Ng, BL, Graham, J, Garnett, MJ, McDermott, U, Nik-Zainal, S, Campbell, PJ, Stratton, MR