KL and systemic sclerosis: These results suggest that either the downregulation of α-Klotho and TRPC-1 or the preferential binding of the upregulated anti-angiogenic VEGF165b isoform to VEGFR-2 may prevent the formation of the VEGF165/VEGFR-2/TRPC-1/sKl molecular complex on the plasma membrane of SSc-MVECs, with consequent negative effects on cellular homeostasis and angiogenesis.