Effects of knockdown p62 on cell migration in Tra/Nac zebrafish embryos. MCF-7 cells were transfected with non-specific control or p62 siRNA, respectively. Thirty embryos were injected for each group and approximately 150 CM-Dil labelled MCF-7 cells were injected into each 2 dpf Tra/Nac zebrafish embryos. Metastasis was measured under the fluorescent microscope at 3 days post-implantation. Some of the embryos were died at this stage. (A) Tra/Nac zebrafish embryos at 2 dpf transplanted with MCF-7 non-specific control and MCF-7 p62 siRNA. The implanted tumour cells can be seen in red (red fluorescent microscope). Presence of migrated tumour cells from yolk sac to the tail is indicated with a black arrow. (B) Percentage of zebrafish which presented any form of metastasis in the total number of injected zebrafish in the experiment. (C) The corrected total cell fluorescence (CTCF) was measured using the formula: CTCF= integrated density − (area of selected cell × mean fluorescence of background readings) for each imaged zebrafish. Scale bar, 500 µm. **P < 0.01, two-tailed Student’s t-tests. Error bars represented mean ± standard deviation.