PPP1R1B and non-small cell lung carcinoma: To address our hypothesis that DARPP-32 drives EGFR:ERBB3 heterodimerization to evade EGFR TKI-mediated cell death, we performed immunoprecipitation studies to assess potential EGFR and ERBB3 interactions in DARPP-32-modulated EGFR-mutated NSCLC cells.