Table 2. Four distinct error types and their definitions.

Error type	Definition	Example
Simplicity region	Sequence called in regions having an unusual composition of nucleotides such as GC/AT-rich and homo-/copolymer sequences.	Fig 2A–2C
SNV cluster	Multiple (three or more) variant calls detected in relatively small genomic regions (up to 50 bp).	Fig 2D
Peripheral sequence read	Variant calls that occur near to (within 5 bp) of either the start or end of reads.	Fig 2E
Base inversion	Sequential calls of 2–3 bp detected with REF-ALT inverted bases.	Fig 2F–2H