CD44 and cancer: The higher level of chemotherapy-resistant proteins ABCB1, CD44, GSTP1, PAICS, AXL, ANXA2, HSPB1, ICAM1, and MMP-1 etc. and the lower levels of LOX, HIC2, HRG, COL1A1, HTRA1, AEBP1, and MAP2K5 proteins that related with the enhanced drug sensitivity and growth suppression of cancer cells were concentrated in ADR/Exo.