Because the proliferation-invasion switch is the basis of therapy resistance, metastasis and cancer mortality39,40, we showed phosphorylation of YBX1 in basal-like HNC cells with active PI3K signalling confers an oncogenic role for this factor, while unphosphorylated YBX1 acts as a suppressor of metastasis in mesenchymal-like cells with inactive PI3K signalling. Here, PIK3CA is linked to cancer.