FIRRM and osteosarcoma: By overlapping the transcriptomic data derived from osteosarcoma U2OS and chondrosarcoma SW1353 cells overexpressing the L-methioninase (i.e., methionine-deprived cellular environment), we found 332 genes (1 + 8 + 32 + 291) whose expression was downregulated (Fig. 5A), among which C1orf112 (Chromosome 1 open reading frame 112) was the only gene whose expression was positively correlated with cellular content of methionine and localized to mitochondria in all 15 bone tumor cells from CCLE database (R > 0.5, p < 0.05) (Fig. 5A, B).