highly significantP -value < 10 -16
The C > A mutations observed were associated with highly significant sequence-selectivity, being marked by an excess at CpCpT (NGCII082, odds ratio (OR) = 3.2, P -value < 10 -16 , χ 2 test) or TpCpA sites (NGCII092, OR = 1.7, P -value < 10 -16 , χ 2 test) and extensions of these motifs (Materials and methods; Note 6 and Figure S6 in Additional file 1 and Table S14 in Additional file 6 ).