The time derivative of the amount of product of this process, estimated with either La Manno et al.’s 2018 steady state model or Bergen et al.’s 2020 dynamical approach, strongly correlates with flow along low-dimensional cellular state space. The software cuff·diff estimates read uncertainty due to a type of this process with a beta distribution, which contrasts with the Bayesian approach of the MISO model. The ratio of molecules that have and have not undergone this process gives the (*) “velocity” used to predict the future states of cells. Analyses of a form of this process are either count-based or isoform-based (-5[1])depending on whether they entail a full transcript reconstruction. (-5[1])Single-cell RNA sequencing reports a form of this process in terms of differential exon usage. For 10 points, name this process whose “alternative” (10[1])form (10[1])can produce (10[1])multiple (10[1])transcripts (10[1])depending on which introns (10[1])are excised. ■END■ (10[3])