GREM1-knockdown cells showed much lower tumour growth rates than control cells with dramatic reduction in the tumour volume [mean ± SD (mm3): 790.412 ± 219.830 (SKBR3-shCtrl) vs. 97.782 ± 27.008 (SKBR3-shGREM1), 6 xenografts/each cell line] (Fig. 3i), whereas overexpression of GREM1 resulted in significantly increased tumour volume [mean ± SD (mm3): 304.496 ± 65.917 (SKBR3-mock) vs. 559.187 ± 137.707 (SKBR3-GREM1), 4 xenografts/each cell line)] (Fig. 3j). The gene discussed is GREM1; the disease is neoplasm.