Simon LS, Keshav V, Baharozian C, et al. - Researchers conducted this pilot study to evaluate the potential association of a thrombospondin 1 gene (THBS1) single-nucleotide polymorphism (rs1478604) with thrombospondin 1 (TSP-1) mRNA expression, as well as the risk of pterygium. DNA and RNA were isolated from peripheral blood samples obtained from healthy volunteers (n = 39). DNA was also isolated from conjunctival tissue samples obtained during pterygium excision surgeries (n = 42). Compared with TT and CT genotypes, the expression of TSP-1 mRNA was significantly lower in the peripheral blood of normal subjects who were homozygous for the C allele of rs1478604 (CC). The C allele of rs1478604 was linked to lower TSP-1 expression and a higher risk of pterygium, suggesting that TSP-1 may play a role in pterygium pathogenesis.