Tissue content of gallium(III)-metallated corrole (S2Ga) measured by ICP-MS at 6 h after systemic delivery alone or by NBPs in 8-week-old female BALB/c mice (n = 6 per treatment) bearing orthotopic 4T1 tumours. Statistical significance determined using two-way multiple-comparisons ANOVA (95% CI) and Šídák post hoc test. Data are presented as mean +/- s.d.