GSPT1 and cancer: CC‐885, the pioneering GSPT1‐targeting degrader identified from a library of analogs derived from immunomodulatory drug lenalidomide, defined GSPT1 as a CRBN “neosubstrate” specificity on the CRL4CRBN E3 ubiquitin ligase, transforming GSPT1 from an “undruggable” target to an attractive, promising target for the treatment of pan‐cancer (especially for AML).