SPDEF and breast adenocarcinoma: SPDEF bound to the non‐coding upstream regions of MUC5AC and MUC5B (Figs 7A, 8A, and EV5), which is in part consistent with SPDEF binding sites identified by ChIP‐seq using a MCF7 breast adenocarcinoma cell line (Figs 7A, 8A, and EV5; Fletcher et al, 2013).