PECAM1 and neoplasm: In a subcutaneous xenograft tumor model, where a 1:1 ratio of human lung A549 cells with parental HEK293 cells or HEK293 cells expressing IL‐24 was employed, the results indicated a reduction in tumor growth, reduced CD31 positivity as observed in immunostaining, and significantly lower hemoglobin levels in tumors containing HEK293 IL‐24, further corroborating the reduction in angiogenesis upon IL‐24 treatment (Ramesh et al. 2003).