CD44 and ovarian neoplasm: High number of CD44+ cells in early stage HGSOC correlated with shorter PFSExpression correlated with advanced HGSOC, p53 positivity, tumor grade, and chemoresistanceCD44+ cells are overrepresented in recurrent compared to primary HGSOCIncreased CD44v6+ cell numbers in primary ovarian tumors correlated with shorter OSCD44v6+ cells are overrepresented in metastasesDistant metastases-free survival is better in patients with CD44v6-low tumorsPopulation of CD44+CD166+ cells is abundant in platinum-resistant ovarian cancer