TH at 10–5 M suppressed matrix mineralization of DPSCs in OM compared with TH at 10–6 M. We also analyzed the effect of various concentrations of TH on gene expressions of Runx2, an osteoprogenitor maker, Alp and Type I collagen alpha 1 (ColIa1), early markers of osteoblast differentiation, and osteocalcin, a mature osteoblast marker, by RT-PCR. The gene discussed is BGLAP; the disease is ocular melanoma.