Table 2.

Resistance to B16 melanoma induced by recombinant B7-DC cross-linking antibody. C57BL/6 mice received 10 µg of serum-derived human IgM antibody (sHIgM3) (IgM control antibody), (sHIgM12) or recombinantly cloned human IgM antibody (rHIgM12) intravenously on days −1, 0, and +1. B16 melanoma was injected subcutaneously in the flank on day 0. The width and length of tumours were measured on day 17. The product of width and length was used as an estimate of tumour size. Statistical comparisons were made using rank sum anova (between-group statistical comparisons are shown; the probability statistic for three-group simultaneous evaluation was P = 0·002).

Treatment	Tumour-free (day 17)	Average tumour size (mm2)	s.e.m. (mm2)	P-value
sHIgM39	0/5	265	12	Reference
sHIgM12	5/5	0	0	P < 0·05
rHIgM12	4/5	24	–	P < 0·05