ALCL-cell derived cell lines (SR786, Karpas290, SUP-M2, SUDH1L and DEL), CTCL-derived cell lines (MyLa, Mac-1), and PTCL-NOS (T8ML1) derived cell lines were maintained in RPMI-1640 with 10% fetal bovine serum. Cell lines were validated, as previously described(18 (link),43 (link),44 (link)), and tested for mycoplasma every 6 months by Universal Mycoplasma Detection Kit (ATCC). T8ML1 cell lines were generated from a PTCL, NOS patient(45 (link)), and maintained with supplemented IL-2 RPM1 media. Stable expression of doxycycline-inducible shRNA was generated with lentiviral mediated transduction of plko-Tet-On vectors. Oligo sequences for CSF1R shRNA#1: CCGGACAGGAGAGAGCGGGACTATACTCGAGTATAGTCCCGCTCTCTCCTGTTTTTTG, shRNA#2: CCGGGAATCTCACAGGACCTCTTAGCTCGAGCTAAGAGGTCCTGTGAGATTCTTTTTTG and scramble: CCGGCCTAAGGTTAAGTCGCCCTCGCTCGAGCGAGGGCGACTTAACCTTAGGTTTTT. Knock-down of CBFA2T3 was performed with sigma mission pLKO.1 shRNA vectors, TRCN0000020164 (shRNA #1) and TRCN0000020165 (shRNA #2).