In the article on mesenchymald stem cell targeting of microscopic tumors in the November 1, 2005 issue of Clinical Cancer Research, in the Materials and Methods section, in the Tumor Cells paragraph, the correct concentrations of penicillin and streptomycin are 100 units/mL and 100 ug/mL, respectively.

In the Results section, in the Microscopic Analyses of Tumor Stroma and Surrounding Tissues paragraph, the second sentence should read, as follows: In the first group of mice with s.c. coinjection of tumor cells and tracer TG-hMSCs, as well as in the second group with i.v. administration of tracer TG-hMSCs, the EGFP fluorescence and immunostaining were detectable mainly in cells forming the capillary-like structures (Fig. 2G, H, and I), in the cells within the inner layer of small arterioles (Fig. 3B, C, E, and F), and in connective tissue cells (Fig. 2F). The last sentence in this section should read, as follows: In particular, EGFP-expressing cells were identified in hair follicles (Fig 2A, B, C, and D), in the basal layer of dermis (Fig. 3A and D), and in the endothelial and intimal layers of small blood vessels in the skin overlaying s.c. tumors.

Hung S-C, Deng W-P, Yang WK, et al. Mesenchymal stem cell targeting of microscopic tumors and tumor stroma development monitored by noninvasive in vivo positron emission tomography imaging. Clin Cancer Res 2005;11:7749–56.