SIK1 and metastatic neoplasm: Consistent with RNA expression, the protein level of ATP11B was lower in tumors from Brca1-MSK mice compared with its level in tumors from WT and Trp53+/Co MMTV-Cre (Trp53-MSK) mice (Figure 2E and Supplemental Figure 2B), and it was further reduced in sgATP11b-545 cells and metastatic tumors from sgATP11b-545–carrying mice compared with their respective controls (Figure 2E).