tokens: DESIGN : Intradermally injected human squamous cell carcinoma cells were grown to 40 to 80 mm3 in athymic nude mice and irradiated with 675 - nm light ( 75 J / cm2 , 75 mW / cm2 ) 24 hours after the intraperitoneal injection of SiPc IV ( 1 . 0 mg / kg ) .