The molecular mechanisms underlying the preferential uptake of NIRF dyes by gastric cancer cells primarily involve tumor hypoxia and activation of select OATP genes, such as OATP1B3. Importantly, we demonstrated increased uptake of MHI-148 in situ in perfused clinical gastric tumor samples, which did not interfere with gastritis commonly associated with gastric cancer. Here, SLCO1B3 is linked to gastric neoplasm.