In breast cancer cells with FGFR1 amplification (CAMA1 and MDA-MB-134), FGF2 elevated non-canonical FGFR downstream signaling pathways, especially JAK-STAT pathway, to promote p21 expression and modulate the ratio of p21/CCND1 to drive cell cycle arrest. The gene discussed is CDKN1A; the disease is breast cancer.