ESR1 and breast cancer: For example, KRT18 has been shown to modulate estrogen receptor alpha (ER) signaling by sequestering an ER coactivator, LRP16, in the cytoplasm.[4] KRT19 has been shown to help localize E‐cadherin to the cell membrane, facilitating cell‐cell adhesion.[5] KRT14 is perhaps the most well‐characterized keratin in the context of cancer and has been shown to be concentrated in the leading edge of collectively invading breast cancer cells[6, 7] and to facilitate the invasion of ovarian cancer cells.[8] Keratin expression has also been linked to poor patient outcomes.