PIK3CA and small cell lung carcinoma: BCL-2 has been identified as a possible key molecule in SCLC transformation.[74] In a case report, BCL-2 were found to be overexpressed in ADC with neuroendocrine transformation compared to the initial ADC.[74] Similarly, Niederst et al. discovered several features of SCLC transformation, including activating mutation in PIK3CA, inactivation of TP53 and sensitivity to BCL-2 inhibition.[52] Researchers also mentioned that ABT-263 (Navitoclax), a drug targeting BCL-2 and BCL-XL inhibitors, exhibited marked efficacy against SCLC transformation from EGFR-mutant cell lines.