Objective  To observe and analyze the expression of cysteine-rich61(Cyr61)

a secreted

cysteine-rich

heparin-binding protein encoded by a growth factorinducible immediateearly gene

in a variety of human tumors

in order to explore its role as a new marker for tumor diagnosis.   Methods  HE and immunohistochemical staining were used to detect the expression of Cyr61 in several organ tumor tissue array and 30 human tumors samples.   Results  The expression of Cyr61 was found in human tumor tissue array and in human tumor samples with positive straining in 79% (38/48) and 93% (28/30)

respectively. Strong positive staining was found in the tumors from the brain

esophagus and thyroid. Positive staining was seen in the tumors from the stomach

liver

colon

rectum

lungs

kidneys

uterine

skin

ovary and breasts. Negative staining was defined in the tumors from the prostate

bladder and pancreas.   Conclusion  Overexpression of Cyr61 is seen in many human tumors and the expression is different in different types of tumors. Cyr61 is probably used to diagnose the tumor as a new marker.