LP40-365 is the prototype of a new class of runaway stars, thus far consisting of four members. The atmospheres of the known ``LP40-365 stars'' are dominated by oxygen, neon, and magnesium, and are sprinkled with the ashes of partial oxygen and silicon burning. Possessing masses and radii in the range of 0.2-0.3 Msun and 0.16-0.6 Rsun, respectively, the LP40-365 stars are suggested to be the former accreting white dwarfs that have survived disruption in near-Chandrasekhar-mass thermonuclear supernova explosions. Due to remarkable mass loss, the LP40-365 stars were violently unbound from their companions. Detailed spectroscopic and kinematic analysis is crucial to assess their physical properties, which can be used as boundary conditions for population synthesis modelling aiming to characterise the formation and evolution mechanisms.