To view this video please enable JavaScript, and consider upgrading to a web browser that supports HTML5 video Movie 1 KTR sensor reveals dynamic ERK activity in ESCs growing in serum + LIF. Time-lapse imaging of ERKKTR expressing cells growing in serum + LIF with (left) and without MEKi (right). Frame rate is 20 s, total duration is 101 min. Scale bar: 20 μm. Intermittent ERK oscillations downstream of FGF in mouse embryonic stem cells Dhruv Raina, Fiorella Fabris, Luis G. Morelli, and Christian Schröter Development 2022. 149:None-None; doi: 10.1242/dev.199710 Download Original Video