KRAS and non-small cell lung carcinoma: Encouraged by these results, in this study we designed and synthesised a series of compounds with structure of urea or thiourea on the basis of the lead compound Kobe0065, and examined their cytotoxic effects on NSCLC A549 cell, in order to find small molecule that could target K-Ras protein, block K-Ras-effector proteins interactions and significantly inhibit the growth of NSCLC.