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Small heat shock proteins (sHSP) play an important role in the resistance to anticancer drugs. We examined the expression of the sHSP family, HSP27 and α-crystallins, in human retinoblastoma with and without preoperative chemotherapy.Eighteen enucleated eyes from patients with retinoblastoma were used. Six patients had undergone chemotherapy before enucleation. Formalin-fixed, paraffin-embedded tissue sections were processed for H&E staining and examined by immunohistochemistry using anti-HSP27 and α-crystallins antibodies.Eleven of 12 cases with no history of preoperative chemotherapy showed weakly positive or negative staining for HSP27, whereas six and five cases were strongly positive for αA and αB-crystallin, respectively. In the six cases with a history of chemotherapy, several viable retinoblastoma cells remained. Immunoreactivity for HSP27 and αB-crystallin was strongly detected in the cytoplasm of viable retinoblastoma cells, while αA-crystallin immunoreactivity was less marked. Immunoreactivity for HSP27 was significantly higher in retinoblastoma cases with preoperative chemotherapy than in those without chemotherapy (p<0.0001). In contrast, immunoreactivity for αA-crystallin was significantly lower in cases with chemotherapy than in cases without chemotherapy (p<0.01).HSP27 and αB-crystallin, but not αA-crystallin, were highly expressed in viable tumour cells after chemotherapy, suggesting that HSP27 and αB-crystallin may protect tumour cells from apoptotic signals produced by anticancer drugs in retinoblastoma.