Thus, generation of a molecular differentiation model allows classification of patient-derived breast cancer-associated fibroblasts as early onset CAFs defined by relatively low ACTA2 positivity and moderate secretory profile and mostly exhibiting ECM remodelling qualities with high COL1A, TNC, MMP2, LOX and LOXL2 levels with concomitant decrease in CAV1 and CD44. The gene discussed is CD44; the disease is breast cancer.