HSP90AA1 and myopia: One study found the increased expression of activated STAT3 in the retina of FDM guinea pigs, suggesting that STAT3 may be involved in the formation and development of myopia.[49] As a signaling protein, it could act on the photoreceptor outer segments of the retina,[50] and continuous chronic stimulation from STAT3 could cause retinal lesions and aggravate myopia.[51] HSP90AA1 is a heat shock protein (HSP) and its functions are related to immunity, structural maintenance and repair.