SNAI1 and malignant colon neoplasm: When single or episomal Snail cells were cultured with 100 ng/mL DOX, the level of Snail RNA expression in the single-copy Snail line (Snaillo) was comparable to other Snail-expressing colon cancer cell lines, whereas the episomal–Snail line (Snailhi) expression was 75-fold higher (Fig. 1c).