As part of our investigation of the possible molecular mechanisms involved in the formation of MPE associated with EGFR-L858R–mutant lung adenocarcinoma, we used public GEO data (GSE11729), real-time RT-PCR, and flow cytometric analyses to determine whether chemokine receptors are differentially expressed between H1299-EGFR-L858R and H1299-EGFR-WT cells. The gene discussed is EGFR; the disease is lung adenocarcinoma.