SLF induces cell spreading of adherent TF-1 on fibronectin-coated wells. TF-1 cells were plated on fibronectin-coated wells and incubated for 15 minutes at 37°C. Wells were washed twice with RPMI-BSA medium. The medium without SLF (A), or with SLF (10 ng/mL) (B) was added to the wells and the wells were further incubated for 10 minutes before being photographed at 400 × magnification.