SNAI1 and triple-negative breast carcinoma: As shown in Fig. 1a and Supplementary Table 1, the majority of Snail1 was localized in the nucleoplasm in human triple-negative breast cancer HCC1806 cells, notably, a small percentage (approximately 4%) of HCC1806 cells showed Snail1 co-localized with the nucleolar marker B23, in which about ~18% of total nuclear Snail1 protein was attributable to the nucleolus (Supplementary Table 2).