GRPR and lung cancer: High affinity NMBR (Ki = 0.15 nM) and moderate affinity GRPR (Ki = 1.0 nM) non-peptide antagonist PD176252 [186] (Figure 1C, [186]) significantly inhibited NCI-H1299 proliferation (and was more potent than PD168368) and considerably inhibited lung cancer colony number in vitro [187].