C3-liposome treatment results in reduced tumour volume of treated established tumours. Established 4T1 tumours were treated by subcutaneous peritumoral injections of PBS or liposomes encapsulating TLR agonists starting on day 0, and every other day for a total of 7 injections. Tumour measurements were made before all injections, showing (A) injected tumour volume, and (B) distal non-injected tumour volume (mm3). By day 8, and through the end of the study, only C3-liposomes significantly reduced injected tumour volumes (*p Value < .05, compared to PBS). Data are expressed as mean ± standard error (n = 3–4).