RARA and acute promyelocytic leukemia: The average SERS spectra of genomic DNA from bone marrow aspirations obtained from APL patients categorised based on the presence or absence of PML‐RARA transcripts (MRD positivity) are shown in Figure 1A, revealing distinctive SERS bands associated with guanine (680 cm−1), adenine (730 cm−1), cytosine (790 cm−1), the phosphate backbone (905 cm−1) and 5‐methylcytosine (1005 cm−1) (Figure 1A).