CD44 and cancer: For example, the expression of several metastasis-associated genes was found to be higher in cells with than without the CD44+/CD24- phenotype, and only malignant cell lines with the CD44+/CD24- subpopulation were able to invade matrigel, indicating that CD44+/CD24- cancer cells are more metastatic than non-CD44+/CD24- cells [21,22].