``` zcat /home/lp113/hbc/PIs/xia_feng/feng_RNAseq_human_neurons_hbc05102/data/combined/RegR3_combined_R2.fastq.gz | seqkit sample -p 0.95 -s 11 | seqkit head -n 150000000 -o RegR3_combined_R2_sub.fastq.gz ```