Table 1. Uncertain risks associated with gene drive in general
(I) EscapeAccidental laboratory release, cross‐breeding, or gene flow can potentially allow a drive to move beyond its target population(s)
(II) Ride alongIt is possible that a foreign DNA sequence inserts itself within the gene drive cassette mid‐drive, thus allowing unwanted traits to “ride along” on the spreading drive. If this inserted DNA sequence brings up, unluckily, a benefit to its carriers and a detriment to humans, it will spread, for good and bad
(III) Ecological impactEven when the new traits’ direct impact on a target population might be understood, the drive may have side effects on the surroundings, and these are difficult to estimate and quantify
  • “Reversal” drives have been proposed to undo the effects of a prior drive [9], but to our knowledge, all still leave a pseudo‐gene drive cassette within the genome.