Transcriptional differences between malaria parasites can arise from spontaneous changes both at a genetic (A) or epigenetic (B) level or can occur as a response to an external cue (C). In some cases, responses to external cues may result in an epigenetic alteration, a mechanism that would share features of both B and C (box at the bottom). SNP, single nucleotide polymorphism; CNP, copy number polymorphism. Llorà-Batlle O, Tintó-Font E, Cortés A. Transcriptional variation in malaria parasites: why and how. Brief Funct Genomics. 2019. PMID: 3111483