We found that the expression of STC was down-regulated significantly in the kidney of infected brown trout at 6 wpe, and undetectable 8–12 wpe, suggesting that T. bryosalmonae infection results in progressive down-regulation of calcium/phosphate metabolism activity in host renal cells, however, further investigations are needed to determine the function of STC, as well as their role in suppression of calcium/phosphate in fish during parasite infection. This evidence concerns the gene STC1 and parasitic infectious disease.