AbstractTo search for a marker that predicts the efficacy of radiation therapy in human cervical cancer, gene expression profiles between parental SiHa cervical cancer cells and radiation‐resistant SiHa/R cells have been compared by the microarray technique. Microarray and Northern blot analyses demonstrated that the ICAM‐3 expression was upregulated in SiHa/R cells. This increased expression of ICAM‐3 in SiHa cells enhanced cell survival by about 34.3% after a 2 Gy dosage of radiation. In addition, SiHa/ICAM‐3 cells showed a 2.45‐fold higher level of FAK phosphorylation than that of the control cells. In tumor specimens, ICAM‐3 staining was restricted to tumor stromal endothelial cells and lymphocytes. The overexpression of ICAM‐3 was significantly more frequent in radiation‐resistant cervical cancer specimens when compared with radiation‐sensitive specimens (83.3% vs. 35.3%; p = 0.015). With these observations, we can suggest that an increased expression of ICAM‐3 is associated with radiation resistance in cervical cancer cells and the expression of ICAM‐3 can be used as a valuable biomarker to predict the radiation resistance in cervical cancer that occurs during radiotherapy. © 2005 Wiley‐Liss, Inc.