NCI-H23 is a cell line exhibiting epithelial morphology isolated from the lungs of a black male with non-small cell lung carcinoma (NSCLC), specifically adenocarcinoma. The cells carry the mutation of K-ras 12 and a mutation in the codon 246 (ATC →ATG, isoleucine -> methionine) of the p53 gene. The cells express C-myc, L-myc, v-src, v-abl, v-erb B, c-raf 1, Ha-ras, Ki-ras and N-ras RNAs.

Cell lysate was prepared by homogenization in ice-cold modified RIPA Lysis Buffer (50mM Tris(pH 7.4)，150mM NaCl，1% Triton X-100, 1% deoxycholate, 0.1% SDS) with cocktail of protease inhibitors. Cell debris was removed by centrifugation. Protein concentration was determined by Bradford assay. The cell lysate was boiled for 5 min in 1 x SDS loading buffer (50 mM Tris-HCl pH 6.8, 12.5% glycerol, 1% sodium dodecylsulfate, 0.01% bromophenol blue) containing 5% b-mercaptoethanol.