Heat shock, other environmental and pathophysiological stress stimulate synthesis of heat shock proteins (HSP) family. These proteins enable the cell to survive and recover from stressful conditions but as yet incompletely understood mechanisms. Beside its role in thermotolerance, it plays a role in cell proliferation and drug resistance which makes this protein of special clinical interest. Published data suggest that HSP27 is related to estrogen in breast and to estrogen and progesterone in the endometrium. It has been shown that some but not all estrogen positive breast cancers express HSP27, and overexpression has been associated with the degree of tumor differentiation, and response to hormonal therapy (Tamoxifen). In endometrial carcinomas, the presence of HSP27 is correlated with the degree of tumor differentiation as well as with the presence of oestrogen and progesterone receptors. Studies suggest that detection of HSP27 in endometrial carcinoma, should not be considered as a method for identifying hormone-responsive tumors or indicator or presence of estradiol receptors. In the cervix HSP27 is a marker of cell differentiation, and is highly expressed during the process of squamous metaplasia. Expression in the ovary is still controversial and requires further confirmation of recent observations.