We report the recent progress of interband cascade (IC) lasers based on InAs/Ga(In)Sb/AlSb type-II quantum wells. For the 4.5-micrometers IC lasers, the internal loss was 11.6 cm-1 and the internal quantum efficiency was 460% at 90 K. When mounted epi-side down on diamond, cw operation was observed with an external quantum efficiency (EQE) of 193%, a cw output power over 500 mW, and a threshold current density as low as 35 A/cm2 at 80 K. Dual-wavelength IC laser was also demonstrated. The device lased simultaneously at 4.482 and 4.568 micrometers . At 110 K, a peak output power of 150 mW per facet was achieved with 5-microsecond(s) pulses at 1-KHz repetition rate. The threshold current density, average EQE, and peak output power of a 0.4-mm long device were 119 A/cm2, 278%, and 150 mW per facet, respectively.