ALK and pericardial effusion: As depicted in Figure 2B, a total of 10 actionable alterations were identified in pericardial effusion-cfDNA and pericardial effusion-sDNA of the 26 patients, including MET amplification (27%), EGFR L858R (19%), EGFR T790M (15%), EGFR E746_A750delELREA (exon 19 deletion, 12%), EGFR L861Q (8%), KRAS G12C (8%), EML4-ALK (exon 18: exon 20) fusion (4%), EML4-ALK (exon 20: exon 20) fusion (4%), EML4-ALK (exon 6: exon 20) fusion (4%), and ERBB2 Y772_A755dupYVMA (4%).