On Lena's left forearm there are some scenes where a black marking that looks like a tattoo of an infinity symbol (a sideways 8) is visible. In other scenes it's clearly absent (such as when Lena takes a sample of her own blood in the village with the trees). In most movies I would call that a continuity error, but in Annihilation it's almost certainly both deliberate and significant. I also thought I saw a marking like that on Kane's forearm during the video with the knife (on the memory card left in the mess hall), though I could be remembering it wrong.
What are all the scenes in which we see infinity sign tattoos/markings on characters' arms, and on which characters?