PTK2 and ovarian cancer: The present link between HK2 and FAK/MEK-1/ERK1/2 activation, leading to MMP9/NANOG/SOX9 expression and increased ovarian cancer metastasis and CSC properties, suggests that targeting HK2/FAK/MEK-1/ERK1/2 signaling may be a promising therapeutic alternative, either as mono therapy or in combination with other treatments.