RET and atrial fibrillation: In December 2019, next-generation sequencing was performed on pleural effusion sample of patient using a 520-gene panel (Burning Rock Biotech, Guangzhou, China) and identified 3 concurrent RET gene fusions: CCDC6-RET (C1:R12) (allele frequency [AF]: 38.67%), LINCO1264-RET (intergenic: R12) (AF: 24.95%) and SEMA5A-RET (S5:R12) (AF: 6.05%) (Fig. 2A–C).