Table III. Sequence specificity of mutations in Sµ and Sγ3 segments from wild-type splenic B cells activated with LPS + IL-4.

GL 5′ Sµa	P-valueb
Percentage mutations at G/C nucleotides
55% (31 mutations)c	0.138
43% G/C content
Percentage mutations at hotspots
61% (31 mutations)	0.004
35% hotspots in sequence

^aSegments amplified using the 5µ3 and 3µ2 primers.

^bDifference from random by Fisher’s exact test.

^cSequences shown in Supplementary figure S10.