- ✂️ the head of round-head worm => new round head formed. ✂️ the head of flat-head worm => new flat head formed. What shape will it be if we ✂️ the head of a worm with 50:50 round + flat stem cells? Check out this exciting review by @drmichaellevin.bsky.social lab! #chimerism doi.org/10.1016/j.cd...Feb 6, 2026 19:13