CHRM1 and myeloid sarcoma: Currently, two other classes of GPCR antagonists claimed to induce remyelination are under clinical evaluation: the selective M1 muscarinic acetylcholine receptor antagonist PIPE-307 (which blocks Gq/11-coupled M1 receptors) has progressed to Phase II clinical trials for Relapsing-Remitting MS (RRMS); while the LPA1 receptor antagonist PIPE-791 is being evaluated in Phase I trials, intended for the treatment of progressive MS forms, which have thus far proven difficult to intervene against [41].