PHF20 and neoplasm: Aside from the alterations seen in primary SC tumor tissue, the relapsed SC acquired a novel PHF20-NTRK1 fusion where PHF20 intron 2 fused to the intron 4 of NTRK1 at a high variant allele frequency (VAF) (Table 1 and Fig. 2a), resulting in a PHF20-exon 2: NTRK1-exon 5 fusion mRNA with potential in-frame translation (as depicted in Fig. 2b).