Objective:1．To detect the location where CCR7 is expressed in colorectal cancer SW480 cells by immunohistochemisty．2．First,examine the changes of CCR7 expression in colorectal cancer SW480 cells,non-small-cell lung carcinoma SPC-A1 cells,and nasopharyngeal carcinoma CNE-2 cells after the cells were exposed to different X-ray irradiation doses after 24 and 48 hours;evaluate the CCR7 expressioninSPC-A1 cellstreatedbya single 8Gy dose and 2Gy/day for 6 days that is equal to a single 8Gy in biology effect after 24 and 48 hours,respectively;investigate the effects of irradiation,chemicals and concurrent X-ray irradiation+chemicals on CCR7 expression in CNE-2 cells after 48 hours．