CD28 and hematologic disorder: These G2 CARs have proven to be very effective, with Yescarta (a CD28 G2), Kymriah (a 4-1BB G2), BREYANZI (a 4-1BB G2), TECARTUS (a CD28 G2), and ABECMA (a 4-1BB G2) receiving regulatory approval for the treatment of several hematological malignancies.